he Ultra-Chron collection adopts carbon: an innovative material that is both strong and light, and now being used for the first time in a Longines watch case. Powered by a Longines’ exclusive high-frequency movement, beating at 36 000 vibrations per hour, this model draws inspiration from an iconic 1968 watch with a distinctive cushion-shaped case. Combining innovation and precision, each Ultra-Chron Carbon offers a unique design and is fully chronometer-certified by TimeLab.
Launched in 1968, the Ultra-Chron Diver made history as the first diver’s watch to feature a high-frequency movement. At the time, Longines had already established itself as an expert in this technology, having patented it in 1910 for use in sports timekeeping. In 2022, the brand unveiled a new generation Ultra-Chron, which paid tribute to the 1968 model while incorporating the latest technological innovations.
Today, Longines continues to innovate by introducing a new Ultra-Chron model with a carbon case, a first for the brand. This material, known for being both ultra-resistant and lightweight, is widely used in cutting-edge industries such as aeronautics, a field with which Longines has been closely associated for over a century. The 43 mm-diameter case is crafted from strips of unidirectional carbon fibre and epoxy resin, which are then placed into a mould and heated to a high temperature, compressed under high pressure, and finally cold-cut. It then takes on the iconic cushion shape of the Ultra-Chron case.
This unique manufacturing process creates random patterns in the layout of the fibres, making each case visually unique and giving it a strong identity. Thanks to carbon’s lightweight properties, this new model weighs less than 80 grams, including both the watch and strap. It is water-resistant up to 30 bars (300 metres).
The titanium bezel is fixed and features an aluminium insert engraved with a scale numbered in increments of 10. The case back and screw-down crown are also in titanium. Beneath a sapphire crystal with multi-layer anti-reflective treatment, the sand-blasted anthracite dial features a chapter ring marked by twelve applied silver indexes. These, along with the grey PVD hour and minute hands, are coated with a Super-LumiNova blue luminescence treatment.
Like the other models in the collection, the Ultra-Chron Carbon is powered by the exclusive Longines high-frequency calibre L.836.6. This movement oscillates at 5 Hertz, or 36 000 vibrations per hour. Compared with conventional mechanical movements, it offers greater stability in response to shocks and changes in position caused by wearing the watch. Equipped with a silicon balance-spring and innovative components, this calibre is also up to ten times more resistant to magnetic fields than the ISO 764 standard.
This watch is also fully certified as a chronometer by TimeLab, an accredited independent watch testing laboratory in Geneva. In keeping with the ISO 3159 standard, the qualification process subjects the finished product to a 15-day testing period during which the entire watch is put through a series of functional tests in various positions, repeated at three different temperatures, 8°C, 23°C and 38°C, to confirm its accuracy.
The Ultra-Chron Carbon is fitted with a black technical fabric strap featuring a titanium buckle. Embracing dark tones, the watch is presented in a bespoke black box.
TECHNICAL SPECIFICATIONS
REFERENCE NUMBER L2.839.4.52.2
CALIBRE
- High-frequency (5Hz) self-winding mechanical movement
- Exclusive Longines calibre L836.6
- Entire watch chronometer-certified by TimeLab
- 111⁄2 lines, 25 jewels, 36 000 vibrations per hour
- Resistant to magnetism (ISO 764), with silicon balance spring
- Power reserve: up to 52 hours
FUNCTIONS
- Hours, minutes, seconds
CASE
- ø 43 mm; thickness 14 mm
- Cushion shape, carbon case middle with titanium structure
- Sapphire crystal with multi-layer anti-reflective coating on both sides
- Fixed titanium bezel with aluminium insert
- Screw-down titanium crown
- Screw-down titanium back
- Ultra-Chron logo stamped on the case back
- Distance between lugs: 22 mm
- Total weight (watch + bracelet): up to 80 g
DIAL
- Sandblasted anthracite
- 12 applied silver indexes with Super-LumiNova blue luminescence treatment
- Original Ultra-Chron logo applied
HANDS
- Grey PVD (hours, minutes, seconds), with Super-LumiNova (hours, minutes) blue luminescence treatment
WATER-RESISTANCE
- Up to 30 bar (300 metres)
STRAP
- Black technical fabric, with titanium buckle