The Mühle-Glashütte S.A.R. Rescue-Timer LUMEN is a 42.0 mm, 13.5 mm-high automatic diver-style tool watch whose defining feature is a dial completely coated in Super-LumiNova. Its specifications are strong on paper: 100-bar water resistance, a 41-hour power reserve, and a rubber bezel and screw-in crown. It suits buyers who want a large, legible watch for low-light use and who accept a bold case. It is a poor fit for anyone wanting a slim or understated dress watch.
This review draws on Mühle-Glashütte’s own 2024 catalogue, its collection pages, its published design history, and observed retailer listings. The figures below are manufacturer specifications or listing data. They are not independent measurements. We did not time the lume, check accuracy, or wear the watch, so comfort and real-world performance are not assessed here.
What makes the LUMEN dial different
Most luminous watches apply Super-LumiNova to the hands and hour markers and leave the dial dark. The LUMEN version coats the entire dial in Super-LumiNova, so the watch is meant to read as a glowing surface in the dark rather than a set of glowing points. According to Mühle-Glashütte’s 2024 catalogue, the skeletonised hands are black-coated, and they sit over a cream-coloured luminous background. The date at 4 o’clock remains visible against that background.
Mühle-Glashütte describes this as a variant focused on night legibility. The catalogue does not give a measured glow duration or brightness figure for the dial, so the claim of superior night reading is the manufacturer’s, and it should be judged by looking at the watch in your own conditions.
The Tool Desk
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- 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.
Case size and thickness
The catalogue lists the case as stainless steel, 42.0 mm in diameter and 13.5 mm high. Those numbers are the most important physical facts for buyers, because the case height determines how the watch sits under a cuff and how much it protrudes from the wrist. The 13.5 mm figure is a catalogue dimension; it does not describe comfort.
The case also includes a 4 mm anti-reflective sapphire crystal with a magnifier ground into its underside, a rubber bezel, and a screw-in crown. The magnifier is a design detail that aids reading the dial at close range; the catalogue does not quantify its magnification.
Rank #2
- 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.
Movement and power reserve
The catalogue specifies an automatic SW 200-1 movement in a Mühle-Glashütte configuration. The listed modifications include Mühle’s woodpecker-neck regulation and a stop-seconds function, which lets the wearer halt the seconds hand while setting the time. Quick date correction is also specified, and the power reserve is listed as 41 hours.
These are published specifications. The catalogue does not state an accuracy tolerance or the results of any timing test, so the watch’s rate in daily wear is not established by this review.
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- 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.
Water resistance
The catalogue gives a water resistance rating of 100 bar. A bar rating comes from a static pressure test in a laboratory, and it is not a recommendation for diving or sustained underwater use. Treat the rating as an indication of protection against splashes, rain, washing and accidental immersion, and check the manufacturer’s own care instructions before using the watch in water.
The rescue-service origin
Mühle-Glashütte says the Rescue-Timer’s function and design were substantially shaped by leaders of the DGzRS, the German maritime rescue service. The company identifies robustness and legibility by both day and night as central aims of development. It also states that rescue crews have tested the Rescue-Timer since 2002. This is the manufacturer’s account of its own history, and it has not been independently audited.
Rank #4
- 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
The 2024 catalogue reproduces a line from instructions given to rescue-service personnel: “In your tough day-to-day work as experienced sailors, there’s one thing you shouldn’t do: protect your S.A.R. Rescue-Timer in any way, shape or form!” The quote is attributed to the test instructions as printed by Mühle-Glashütte; the source does not name an individual speaker.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Strap configurations and references
The LUMEN is offered with more than one strap. The catalogue lists canvas, rubber and metal options, but it does not tie each option to a reference number. Retailer listings supply the reference numbers used in the table below.
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Best Value
- 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.
| Reference | Strap configuration | Source |
|---|---|---|
| M1-41-08-KB | Black rubber strap | Retailer listing, which reports principal specifications matching the catalogue |
| M1-41-08-MB | Metal-and-rubber bracelet | Separate retailer listing for this reference |
| Not stated | Canvas strap | Mühle-Glashütte 2024 catalogue; no reference number given |
| Not stated | Metal strap (full bracelet) | Mühle-Glashütte 2024 catalogue; no reference number given |
Because the strap changes both the look and the price, always identify the reference before comparing offers.
Price and availability
At the time of writing, Mühle-Glashütte’s Einsatzuhren collection page showed S.A.R. Rescue-Timer LUMEN variants at €2,200 and €2,350. Wempe’s Mühle-Glashütte nautical instruments page showed LUMEN listings at the same two prices. These are observed page values for different variants, not one fixed price for the watch. They may already have changed, and they do not establish a global price.
Before buying, confirm the following for the exact offer you are considering:
- The reference number, such as M1-41-08-KB or M1-41-08-MB, and the strap or bracelet it includes
- The clasp, and whether it is included
- The market, currency, and whether listed prices include VAT or local taxes
- Current stock and the seller’s return terms
Who the LUMEN suits
- Buyers who want a fully luminous dial and value legibility in the dark above a conventional lume treatment on hands and markers
- Buyers who prefer a large, robust case of 42.0 mm and 13.5 mm, and who like a tool-watch character tied to a rescue-service history
- Buyers who want a mechanical automatic with stop-seconds, quick date correction and a 41-hour reserve, all as published by the manufacturer
It is less suitable for buyers who want a thin, dress-oriented watch, who wear smaller wrists comfortably only with compact cases, or who need independently verified lume duration or accuracy before purchase.
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What the evidence does and does not establish
- Established by the manufacturer: the case dimensions, sapphire crystal, water resistance rating, movement type, power reserve, and the dial design
- Established by listing data: the reference numbers and the observed prices at the time of writing
- Not established: independent lume duration, accuracy over time, comfort, durability in real rescue or sailing use, and how the LUMEN compares with other Rescue-Timer versions in legibility
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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.
