Among its latest batch of novelties unveiled this year at Watches & Wonders Geneva 2024, Montblanc has announced a new version of the 1858 Geosphere 0 Oxygen that expands upon its lineup of oxygen-free adventure watches. Although Montblanc has created a few different Zero Oxygen models within the Geosphere lineup, the latest release takes the oxygen-themed concept one step further, and the new Montblanc 1858 Geosphere 0 Oxygen CARBO2  features a case that is made using CARBO2, which is a carbon fiber-based material that incorporates CO2 reclaimed from the biogas production and mineral waste produced by recycling factories.

From a core design and functionality standpoint, the new Montblanc 1858 Geosphere 0 Oxygen CARBO2 LimiedEdition is largely the same watch as the model that was part of the 8000 series of Geosphere 0 Oxygen watches that debuted at Watches & Wonders Geneva last year. While Montblanc offers a few different models as part of this series, including a version that incorporates the addition of a chronograph, the new Geosphere 0 Oxygen CARBO2 is based upon the worldtimer variant that features an innovative set of globe-based displays on its dial. However, due to its different case materials, the new CARBO2 limited edition has slightly larger dimensions, and it measures 43.5mm in diameter by 13mm thick, compared to the 42m wide by 12.7mm thick case of the previously mentioned model from last year.

The case of the new Montblanc 1858 Geosphere 0 Oxygen CARBO2 Limited Edition is constructed using both titanium and CARBO2 components with the middle case being the section crafted from CARBO2. CO2 from biogas production and mineral waste produced by recycling factories is captured using a calcium dissolution and carbonation process, and the resulting powder consisting of CO2 and CACO3 gets combined with carbon fiber to create the novel case material. Aside from slightly altering its appearance and putting an environmentally friendly twist on carbon fiber, it is unclear whether or not there are actually any performance benefits of CARBO2 compared to traditional forged carbon, although the use of this material on the 1858 Geosphere 0 Oxygen CARBO2 is still noteworthy as it represents the first time that it has appeared in Montblanc’s collection.

The left-hand side of the middle case on the new Montblanc 1858 Geosphere 0 Oxygen CARBO2 is adorned with a stylized outline of the Mont Blanc Mountain, which is engraved into the material and filled with Super-LumiNova and a clear protective varnish. Inspired by old glaciers that appear blue due to their density and lack of oxygen within their structures, the luminous mountain engraving appears white in the daylight, although it glows blue in the dark to match the rest of the Super-LumiNova that is used throughout the dial, hands, and bezel of the watch. To further lean into its blue glacier inspiration, a blue gasket surrounds the crystal on the new 1858 Geosphere 0 Oxygen CARBO2, and this detail appears as a subtle dark blue halo that surrounds the face of the watch.

Protecting the dial of the new Montblanc 1858 Geosphere 0 Oxygen CARBO2 Limited Edition is a domed sapphire crystal with anti-reflective treatment, and this is surrounded by a bidirectional bezel that is fitted with a black ceramic inset with a luminous compass scale. The rest of the watch largely follows in the footsteps of its Geosphere 0 Oxygen predecessors, with a signed crown at 3 o’clock, 100 meters of water resistance, and a titanium caseback that is adorned with an intricate 3D engraving of a mountain (in this case the famous Mont Blanc Mountain). The highly realistic mountain engraving is created using lasers, which both sculpt the design and precisely apply different types of laser-generated oxidation to give the mountain its distinct colors and textures.

The dial of the Montblanc 1858 Geosphere 0 Oxygen CARBO2 offers the same fundamental layout as what can be found on other worldtime versions of the Geosphere, with two centrally-mounted hands for the time, a small running seconds indicator at 9 o’clock, and a date window sitting on the opposite side of the dial at the 3 o’clock position. Additionally, two large globes are positioned on the upper and lower half of the dial, with the globes dedicated to the Northern and Southern Hemispheres. The dial itself is black in color and showcases a sfumato glacier pattern inspired by the interlocking crystals that form glacial ice. The pattern is created using a special technique known as “gratté-boisé” and Montblanc states that it takes approximately four times longer to produce this dial compared to the dials that receive more traditional finishing techniques.

Powering the new Montblanc 1858 Geosphere 0 Oxygen CARBO2 is the same Caliber MB 29.25 automatic movement that can be found inside other Geosphere worldtimer watches. Based upon the core architecture of the popular Sellita SW300, the Montblanc Cal. MB 29.25 runs at a frequency of 28,800vph (4 Hz) with a power reserve of approximately 42 hours, although it features the addition of the brand’s manufacture world-time complication, which provides it with its rather unconventional dual timezone display. Unlike last year’s 1858 Geosphere 0 Oxygen watch, which came with a matching bracelet, the new CARBO2 limited edition has a black rubber strap fitted to its lugs, which features small blue accents with a textile pattern inspired by mountaineering ropes, and it is completed by a folding clasp with an integrated micro-adjustment system.

Regarding the whole “zero oxygen” concept, the idea here is that Montblanc cases up the watches in such a manner that there is no oxygen inside their cases, and this rather unusual detail has two primary benefits. The first advantage is that drastic changes in temperature will not create fogging under the crystal, while the second benefit relates to the longevity of components, and the simple fact that there is no oxygen inside the case means that the various parts of the movement will be less prone to oxidation. While the zero oxygen concept sounds very nice in theory (regardless of the obstacles it may create during service), I am rather curious to know how Montblanc prevents oxygen from entering the case when users pull out the crown to set the time. Given that air is less dense than water and nearly all manufacturers instruct owners not to operate their crowns while submerged, I’d be rather surprised if a standard gasket system was able to prevent ambient air from entering the case over the course of long-term ownership.

Due to its novel case material, the new Montblanc 1858 Geosphere 0 Oxygen CARBO2 is quite a bit more expensive than other worldtimer models from the current Geosphere lineup, and it has an official retail price of $9,100 USD, which places it above many of the brand’s chronographs. Additionally, rather than joining the catalog as a standard-production offering, the new 1858 Geosphere 0 Oxygen CARBO2 will be produced as a limited edition of 1969 pieces, which serves as a reference to the year that Reinhold Messner made the first solo ascent of the Les Droites north face on the Mont-Blanc massif. While I am personally a big fan of Montblanc’s Geosphere series, this latest version undeniably feels rather expensive compared to its direct predecessors, although its CARBO2 case provides a noticeably more utilitarian aesthetic that is a welcome addition to the slightly vintage-leaning design of the Geosphere collection. For more information on the Montblanc 1858 Geosphere 0 Oxygen CARBO2, please visit the brand’s website.