The Montblanc 1858 Geosphere 0 Oxygen Limited Edition honors explorer Reinhold Messner’s historic ascent of Mount Vinson, the seventh peak of the Seven Summits. Limited to 986 pieces, this 43.5mm titanium timepiece features a composite mid-case made from quartz and aluminized basalt fibres combined with CaCO₃ and blue resin. The oxygen-free construction prevents fogging and improves precision, while a luminous engraving of Mount Vinson decorates the case side and a 3D laser-engraved depiction of the mountain adorns the titanium case back. Powered by the MB 29.25 automatic movement, it showcases dual rotating hemispheres, a 24-hour scale, day/night indication, and date. A blue-green rubber strap with fine adjustment completes this adventurer’s companion.