Some links on this page are affiliate links: if you buy through them we may earn a commission, at no extra cost to you.
Choose the Sinn 556 if you want a compact, date-only automatic watch with a quiet everyday profile. Choose the Sinn 104 if you want a larger 41 mm pilot-watch presence, a day-and-date display, and a rotating timing bezel. Both are robust German-made automatics with sapphire crystals, screw-down crowns, low-pressure resistance, 20 bar water resistance, 20 mm strap widths, and magnetic protection to DIN 8309. The meaningful differences are wearability, calendar information, bezel function, case finish, and the movement used to deliver those features.
This is not simply a choice between two sizes of the same watch. The 556 is the restrained all-rounder; the 104 is the more instrument-like pilot watch. Your wrist size, tolerance for visual information, and whether you will actually use a bezel should decide the purchase.
As an Amazon Associate I earn from qualifying purchases.
Quick wins for a faster PC:
Scan for outdated or missing drivers - takes under a minuteDriver Scan →Repair Windows errors before they cause bigger problemsFix Now →Which Sinn should be your first Sinn?
For most buyers seeking one versatile watch, the 556 is the safer default. Its 38.5 mm satinized case, fixed bezel, and time-and-date dial are easy to wear with casual or business-casual clothing. The 104 earns the recommendation when its extra functions are intentional rather than merely attractive: the 41 mm case, day-and-date display, and captive bidirectional pilot bezel give it a stronger aviation-instrument character.
The choice is therefore functional. Select the 556 for compact proportions and visual restraint. Select the 104 for at-a-glance calendar information and elapsed-time timing from the bezel.
Popular on Amazon
- Read Before You Buy — No Video Output: These adapters support charging and USB 2.0 data transfer, but cannot transmit video signals. Except for standard USB webcams (which use USB data only), they are not compatible with HDMI/DisplayPort cables, video-capable USB-C hubs, or docking stations with video output.
- Convert USB-A Ports to USB-C: Designed to connect USB-C earphones, cables, flash drives, card readers, and other USB-C accessories to standard USB-A ports. Plug-and-play with no drivers or software required.
- Aluminum Alloy Housing: Built with a sturdy aluminum alloy shell that aids in heat dissipation and protects against daily wear and scratches. Designed to maintain a stable and secure connection.
- Compact & Travel-Friendly: The ultra-compact design allows the adapter to stay plugged into your device without blocking adjacent ports or adding bulk, reducing wear and tear on your original USB ports.
- 12-Month Warranty: Backed by a 12-month manufacturer warranty for peace of mind. Designed to meet strict quality control standards for reliable everyday performance.
What is the difference between the Sinn 104 and 556?
The table below separates the specifications that change from the baseline features the watches share.
| Axis | Sinn 104 | Sinn 556 | Why it matters |
|---|---|---|---|
| Case | 41 mm diameter; polished stainless steel; approximately 11.9 mm thick | 38.5 mm diameter; satinized stainless steel; approximately 11 mm thick | The 104 has more wrist presence, while the 556 wears more compactly and quietly. |
| Dial and calendar | High-legibility pilot layout with day and date | Minimal time-and-date layout | Decide whether the extra calendar information helps or adds visual activity. |
| Bezel | Captive, bidirectional pilot bezel with minute ratcheting | Fixed bezel | The 104 can time an interval at a glance; the 556 keeps the dial cleaner. |
| Movement | Sellita SW220-1 automatic | Sellita SW200-1 automatic | The 104 calibre supports a day display; the 556 calibre is date-only. |
| Water and pressure rating | 20 bar; low-pressure resistant | 20 bar; low-pressure resistant | Both have the same stated everyday resistance baseline. |
| Crystal and crown | Sapphire crystal; screw-down crown | Sapphire crystal; screw-down crown | These core protection features do not decide the choice. |
| Strap width | 20 mm | 20 mm | Both accept straps specified at 20 mm, subject to end-shape and hardware compatibility. |
Which is better for a small or medium wrist?
The 556 is the logical starting point for a small or medium wrist because its 38.5 mm diameter is 2.5 mm smaller than the 104’s 41 mm. It is also about 11 mm thick rather than approximately 11.9 mm, reducing the visual and physical bulk under a cuff. The satinized finish absorbs light instead of emphasizing the case outline, so the watch tends to look less conspicuous.
Recommended Free Tools
The 104 is not automatically too large. Wrist shape, lug reach, strap stiffness, and personal preference matter as much as diameter. However, a buyer who already knows that compact watches sit better on their wrist should not expect the 104’s extra 2.5 mm to disappear. It is designed to present as a pilot instrument, not as a discreet dress-sport watch.
How the finishes change perceived size
The 104 uses polished stainless steel, which creates brighter highlights and makes its larger case more noticeable. The 556 uses satinized stainless steel, a lower-key surface that supports its understated character. These are documented case finishes, not claims about different steel grades or hardness.
Is the Sinn 104 just a bigger Sinn 556?
No. Size is only one difference. The 104 adds a day indication, a rotating bezel with minute ratcheting, and the SW220-1 movement associated with that calendar configuration. The 556 removes those elements in favor of a fixed bezel, a date-only display, and the SW200-1.
That changes how each watch is read. On the 104, the bezel supplies a second timing scale around the dial and the day-date window introduces more information. On the 556, the dial and case read as a simpler timekeeper. Calling the 104 a larger 556 misses the reason to choose it: its pilot-watch functions.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
Also popular on Amazon
- 5-in-1 USB-C Hub: Experience comprehensive connectivity featuring a Power Delivery input, two USB-A 2.0 ports, a USB-A 3.0 port, and an HDMI port. (Note: The USB-C power delivery input port is only for connecting an external wall charger to power your laptop and cannot power peripheral devices.)
- 90W Pass-Through Charging: Achieve optimal charging with 90W pass-through power to your laptop, supported by a total input of 100W, with the hub reserving 10W for operational efficiency. (Note: Wall charger not included.)
- Quick Data Transfers: Accelerate your productivity with rapid data transfers using a high-speed 5Gbps USB 3.0 port and two 480Mbps USB 2.0 ports.
- 4K HDMI Display: Enhance your visual experience with a hub capable of delivering 4K resolution at 30Hz in both mirror and extend modes. Please note that this hub is compatible with MacBook (macOS 12 and newer), Windows 10 and 11, ChromeOS, and laptops equipped with DP Alt Mode and Power Delivery. Note: This device is not compatible with Linux.
- What You Get: Anker USB-C Hub (5-in-1, 4K HDMI), welcome guide, 18-month warranty, and our friendly customer service.
How do the day-date and date displays affect daily use?
Sinn 104: day and date
The 104 shows both the day of the week and the numerical date. This is useful if you routinely need a complete calendar check without reaching for a phone or another device. It also contributes to the watch’s instrument-like identity, because the dial communicates more than time alone.
Sinn 556: date only
The 556 keeps the numerical date while omitting the weekday. That leaves fewer indications competing for attention and preserves the minimal layout many buyers want from a daily watch. If you rarely need the weekday, the missing display is not a practical loss; it is a visual simplification.
The movements explain the distinction. The 104 uses Sellita’s SW220-1 automatic, while the 556 uses the SW200-1 automatic. Both are specified at 28,800 vibrations per hour, but the calendar configuration is not the same.
What does each bezel do?
The 104’s captive bidirectional pilot bezel
The 104 has a captive bidirectional pilot bezel that ratchets in minute increments. You can align its marker with a minute hand or another reference point and read elapsed time without operating the crown or using a separate timer. Bidirectional movement suits the pilot-watch timing concept, where the bezel is a quick reference rather than a unidirectional safety device.
The Tool Desk
Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →“Captive” describes the bezel’s secured construction; it is not a loose friction ring. Minute ratcheting gives you discrete positions instead of an entirely free-spinning ring, making the setting easier to feel and more likely to stay where you placed it.
The 556’s fixed bezel
The 556’s bezel does not rotate. That keeps the perimeter visually quiet and eliminates the possibility of accidentally moving a timing reference. Choose it if you prefer to time activities with a phone, chronograph, or external timer, or if you simply do not want a second scale on the watch.
Also popular on Amazon
- Sleek 7-in-1 USB-C Hub: Features an HDMI port, two USB-A 3.0 ports, and a USB-C data port, each providing 5Gbps transfer speeds. It also includes a USB-C PD input port for charging up to 100W and dual SD and TF card slots, all in a compact design.
- Flawless 4K@60Hz Video with HDMI: Delivers exceptional clarity and smoothness with its 4K@60Hz HDMI port, making it ideal for high-definition presentations and entertainment. (Note: Only the HDMI port supports video projection; the USB-C port is for data transfer only.)
- Double Up on Efficiency: The two USB-A 3.0 ports and a USB-C port support a fast 5Gbps data rate, significantly boosting your transfer speeds and improving productivity.
- Fast and Reliable 85W Charging: Offers high-capacity, speedy charging for laptops up to 85W, so you spend less time tethered to an outlet and more time being productive.
- What You Get: Anker USB-C Hub (7-in-1), welcome guide, 18-month warranty, and our friendly customer service.
The 104 bezel is documented as a pilot bezel, not a dive-watch bezel. Do not treat its bidirectional action as the safety feature associated with a unidirectional diving bezel.
Do the Sinn 104 and 556 use the same movement?
No. The 104 uses the Sellita SW220-1 and the 556 uses the Sellita SW200-1. Both are automatic movements specified at 28,800 vibrations per hour and protected against magnetic fields according to DIN 8309.
The calibre difference is practical rather than a simple ranking. The SW220-1 supports the 104’s day-and-date indication; the SW200-1 serves the 556’s date-only layout. The available specifications do not establish a reliability, accuracy, or service-interval winner between these installations, so choosing the 104 solely because its calibre number appears different would be unwarranted.
What 28,800 vibrations per hour means here
The stated frequency is 28,800 semi-oscillations per hour for the automatic movements. It is a movement specification, not a promise that one watch will keep better time than the other. No published sales, failure-rate, or head-to-head accuracy statistic establishes such a result.
Are the 104 and 556 equally durable?
At the headline level, yes: both series are specified with sapphire crystals, screw-down crowns, low-pressure resistance, and water resistance to 20 bar. Both also carry DIN 8309 antimagnetic protection in the movement specifications. Those shared features make neither model the obvious choice for basic everyday protection.
The 20 bar figure is the manufacturer’s stated pressure rating. It should not be expanded into an unlimited-use guarantee: water resistance depends on the condition of seals, crown engagement, and maintenance. The published material does not provide a test schedule, impact rating, or service interval, so those details should be confirmed with an authorized seller for the specific watch and market.
Quick wins for a faster PC:
Repair Windows errors before they cause bigger problemsFix Now →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Clear out junk files and repair common Windows errorsFree Scan →Also popular on Amazon
- Dual Converters, Infinite Potential：Includes 2× USB C male to USB A female adapters and 2× USB A male to USB C female adapters. Perfect for a wide range of uses—tablets with Bluetooth keyboards, expand USB ports on macbook, and more. Two different converters for all your daily needs
- Next-Level 10Gbps & 3A Charging: No more slow 480Mbps, this usb to usb c adapter has a transfer speed of up to 10Gbps, allowing you to do more transferring in less time. This usb adapter fits both USB A and USB C charger, supporting up to 3A fast charging
- Upgraded Exquisite Craftsmanship: With an aluminum alloy housing and metal connector, the usbc to usb adapter is extremely durable and sturdy. Rigorously tested to withstand more than 10,000 times of plugging and unplugging, ensuring long-lasting performance
- Broad Compatible: The usb c to usb adapter widely supports all USB C/ USB A devices like laptops, tablets, cellphones, car chargers, and phone chargers. Such as compatible with MacBook Pro/Air 2023/2022, Thunderbolt 4/3 Devices,Apple MagSafe Watch 9/8/7/SE/Ultra, iPad Pro 2022/2021, Samsung Galaxy S23/S20/S10, and iPhone 17/16/15 Pro. Plug and play
- Please Note: To reach 10Gbps speed, keep the cable under 3.3 ft. For USB A Male to USB C adapters, try flipping the USB C connector. USB C Male to USB A adapters support bidirectional 10Gbps transfer within 3.3 ft
Which watch is more versatile as an everyday watch?
The 556 is the more versatile default when “versatile” means unobtrusive. Its smaller satinized case, fixed bezel, and sparse dial can move from jeans to office clothing without making the watch the visual focus. That is an editorial inference from the documented proportions and layout, not a measured popularity claim.
The 104 is more versatile for someone whose daily life benefits from a timing bezel and a full day-date readout. Its polished 41 mm case and pilot bezel are intentionally more prominent. It can still be worn daily, but it communicates a stronger tool-watch identity and may be less discreet under a narrow shirt cuff.
Pick the 556 when
- You prefer a 38.5 mm case and approximately 11 mm thickness.
- You want a date but do not need the weekday.
- You prefer a fixed bezel and a quieter dial.
- You want the lower-key appearance of a satinized case.
- You are buying one watch to cover a broad casual and business-casual wardrobe.
Pick the 104 when
- You specifically want a 41 mm pilot-watch presence.
- You will use a bidirectional bezel for elapsed-time or countdown references.
- You want both day and date on the dial.
- You like the brighter visual character of polished stainless steel.
- The extra information and larger scale are features, not compromises.
How should you use the 104 bezel for timing?
- Rotate the bidirectional bezel until its minute marker aligns with the current minute hand or another chosen reference.
- Start the activity and read the minute hand against the bezel scale as time passes.
- For a countdown, place the remaining-minute marker at the current minute and monitor the hand as it approaches the reference.
- Check the bezel position before relying on the reading, because bidirectional movement can change the reference if the ring is knocked.
This is a simple elapsed-time aid, not a chronograph. The 556 has no equivalent rotating scale, so timing requires its fixed dial plus another method.
Can you use the same strap on both watches?
Both official specifications list a 20 mm strap or belt width, so a 20 mm replacement strap is the relevant cross-model accessory category. Width alone does not guarantee a clean fit. Before ordering, verify whether the strap uses straight ends or fitted geometry, and check the clasp or buckle style and the material.
A strap that measures 20 mm at the lugs can still sit poorly if its end shape conflicts with the case, or if the buckle hardware does not suit your preferred setup. Those listing-level details vary by strap and are not established by the watch specifications.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.What should you check before buying a Sinn 104 or 556?
- Confirm the exact reference and market. Series names can cover model variants, and regional stock or warranty handling can change.
- Measure your wrist and compare proportions. Start with 38.5 mm versus 41 mm and approximately 11 mm versus 11.9 mm thickness; then consider lug reach and cuff clearance in person if possible.
- Decide whether the weekday matters. If you will not use it, the 104’s extra calendar information may be unnecessary visual activity.
- Decide whether you will use the bezel. Choose the 104 for a real timing habit, not simply because a rotating bezel sounds useful.
- Inspect the case finish in your normal lighting. Polished steel emphasizes the 104’s presence; satinized steel keeps the 556 quieter.
- Verify strap compatibility. Both are specified at 20 mm, but end geometry and hardware still need confirmation.
- Read the regional warranty terms. Sinn Japan pages show market-specific pricing and a two-year guarantee; prices, stock, variants, and warranty handling are volatile and should be rechecked for your market at purchase.
What do the official descriptions imply about each model?
Sinn’s catalogue calls the 104 “the classic pilot watch” and the 556 “the elegantly sporty watch.” Those descriptions align with the hardware: the 104 combines the pilot bezel and day-date display with a larger polished case, while the 556 uses a compact satinized case and fixed bezel for a more restrained result.
Also popular on Amazon
- 5-in-1 Connectivity: Equipped with a 4K HDMI port, a 5 Gbps USB-C data port, two 5 Gbps USB-A ports, and a USB C 100W PD-IN port. Note: The USB C 100W PD-IN port supports only charging and does not support data transfer devices such as headphones or speakers.
- Powerful Pass-Through Charging: Supports up to 85W pass-through charging so you can power up your laptop while you use the hub. Note: Pass-through charging requires a charger (not included). Note: To achieve full power for iPad, we recommend using a 45W wall charger.
- Transfer Files in Seconds: Move files to and from your laptop at speeds of up to 5 Gbps via the USB-C and USB-A data ports. Note: The USB C 5Gbps Data port does not support video output.
- HD Display: Connect to the HDMI port to stream or mirror content to an external monitor in resolutions of up to 4K@30Hz. Note: The USB-C ports do not support video output.
- What You Get: Anker 332 USB-C Hub (5-in-1), welcome guide, our worry-free 18-month warranty, and friendly customer service.
Neither phrase is a performance test or an independent ranking. They are useful shorthand for the intended character of each series, while the dimensions and functions above are the basis for a buying decision.
Final decision: 104 or 556?
Buy the 556 when your priority is a compact all-rounder: 38.5 mm, approximately 11 mm thick, date-only, fixed bezel, and satinized steel. Buy the 104 when you already know you want the larger 41 mm format, day-date information, and a captive bidirectional bezel with minute ratcheting.
Windows Errors? Fix Them Before They Spread
Repair common Windows errors and clear accumulated junk for a smoother, more stable PC - no reinstall needed.Free scan · no reinstallOutdated Drivers Are Slowing You Down
One free scan finds every outdated or missing driver and matches the right update for your exact hardware.Free scan · exact hardware matchBoth deliver the same essential durability baseline and automatic frequency, so the decision is not about one being categorically tougher. It is about whether the 104’s additional information and timing function improve your daily use enough to justify its larger, brighter presence.
Frequently Asked Questions
Is the Sinn 104 bezel safe to use for diving?
No conclusion about dive use follows from its specification. The 104 is documented with a bidirectional pilot bezel, whereas dive-watch timing bezels are designed around different safety conventions; treat the 104 bezel as an elapsed-time reference, not as a substitute for a dive-rated timing system.
Does the 556 have a day wheel that can be hidden?
The documented 556 configuration is date-only. Its listed Sellita SW200-1 movement and minimal dial do not establish a weekday display that can be revealed or concealed.
Are Sinn 104 and 556 prices the same in every country?
No. Sinn Japan pages publish market-specific prices and a two-year guarantee, but regional pricing, stock, model variants, and warranty handling can change. Check the dealer or Sinn page serving your market before treating any quoted figure as current.
What does DIN 8309 antimagnetic protection tell me?
It identifies the stated magnetic-protection standard applied to both movements. It does not provide a published accuracy comparison between the watches or guarantee immunity from every magnetic source encountered in daily life.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
