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One free scan finds every outdated or missing driver and matches the right update for your exact hardware.Free scan · exact hardware matchThe Longines Ultra-Chron Carbon, reference L2.839.4.52.2, is a 43 mm high-frequency diver-style watch with a carbon-and-titanium case, a fixed bezel and a 5 Hz automatic movement. Longines states that the complete watch is TIMELAB chronometer-certified and rates it to 30 bar (300 metres). Its official U.S. listing showed $5,550 when checked for this article; that is a regional, time-sensitive price, not a universal quote.
What the Longines Ultra-Chron Carbon is
The reference L2.839.4.52.2 is the carbon-cased member of Longines’ Ultra-Chron line. It pairs the collection’s high-frequency mechanical movement with a cushion-shaped case made from carbon and titanium components. Longines introduced the carbon case in 2025, describing it as the first carbon case used in a Longines watch.
This is a diver-style watch, but its bezel is fixed. It does not provide the rotating elapsed-time scale found on a conventional dive-timing bezel.
Longines Ultra-Chron Carbon specifications
| Specification | Longines-stated detail |
|---|---|
| Reference | L2.839.4.52.2 |
| Case size | 43 mm diameter; 14 mm thick |
| Case shape and construction | Cushion-shaped; carbon case middle with titanium structure |
| Bezel | Fixed titanium bezel with aluminium insert |
| Crown and case back | Titanium screw-down crown and back |
| Movement | Exclusive Longines calibre L836.6; self-winding; 25 jewels |
| Frequency | 5 Hz, or 36,000 vibrations per hour |
| Balance spring and certification | Silicon balance spring; Longines says the entire watch is TIMELAB chronometer-certified |
| Power reserve | Up to 52 hours |
| Water resistance | Up to 30 bar / 300 metres |
| Strap and lug distance | Black technical-fabric strap with titanium buckle; 22 mm distance between lugs |
| Published weight | Up to 80 g, described in the technical sheet as “watch + bracelet”; the listed configuration is supplied on a strap |
| Warranty | Five years on the U.S. product listing |
These are manufacturer specifications, not results from an independent timing or water-resistance test. The TIMELAB certification is stated by Longines; the available specification does not give a specific accuracy range, so one should not be inferred from the certification alone.
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What the 5 Hz movement means
At 5 Hz, the balance completes five oscillations per second—36,000 vibrations per hour. That is a higher operating frequency than the 4 Hz / 28,800-vibrations-per-hour rate common in many mechanical watches. The frequency describes how quickly the regulating organ oscillates; by itself, it does not establish a particular real-world accuracy advantage or service interval.
Longines specifies a silicon balance spring and says the movement resists magnetism under ISO 764. The stated power reserve is up to 52 hours, meaning a fully wound watch can run for that duration under the conditions behind the manufacturer’s rating; it is not a multi-day reserve.
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Carbon and titanium case construction
Longines describes a carbon case middle supported by a titanium structure. The fixed bezel is titanium with an aluminium insert, while the screw-down crown and case back are also titanium. The material mix matters: “carbon” identifies the case middle, not every exterior component.
The technical sheet gives a total weight of up to 80 g using its own “watch + bracelet” wording, although the accompanying materials specify a fabric strap and titanium buckle. Treat the weight as Longines’ published figure rather than a separately measured strap configuration.
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How it connects to the 1968 Ultra-Chron Diver
Longines dates the Ultra-Chron Diver to 1968 and describes it as the first diving watch with a high-frequency movement. The Carbon continues that lineage through its high-frequency calibre and cushion-shaped case design. Its 2025 distinction is the carbon case; it should not be confused with a direct reproduction of the original watch.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Official price listings and availability
At the time of the cited official listings, Longines’ U.S. product page showed $5,550, while its collection page displayed CHF 4,600 for the Carbon model. These are separate market listings in different currencies, not a currency conversion or like-for-like global price. Check the relevant Longines regional page for current price and availability.
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- 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.
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- What You Get: Anker 332 USB-C Hub (5-in-1), welcome guide, our worry-free 18-month warranty, and friendly customer service.
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Sources
- Longines U.S. product page, reference L2.839.4.52.2
- Longines 2025 Ultra-Chron Carbon technical sheet
- Longines Ultra-Chron collection page
- Longines Media Center, “ULTRA-CHRON CARBON,” 1 January 2025
- Longines Media Center, “LONGINES ULTRA-CHRON,” 31 May 2022
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.
