When developing the Lunokhod Prime watch with an 18k rose gold case, Konstantin Chaykin also decided to make the moon sphere of this watch precious. The material he chose was a wonderful 12 mm white South Sea pearl, which Konstantin Chaykin selected from hundreds of candidates because of its excellent spherical shape – it is almost impossible to find a natural pearl with an ideal spherical shape. It is also almost impossible to find such a case in the history of watchmaking where a pearl was used as a functional element of a movement. There is something special about observing the watch being built. It is not just a mechanical process, but a true art in which the meticulous work of the master craftsman is combined with the precision of technical thinking. Assembling a watch is something that can fascinate, inspire and convey a sense of wonder. The movement of the Lunokhod Prime differs from the Lunokhod in the way the minutes are displayed. While the Lunokhod watch has a continuously rotating minute hand, the Lunokhod Prime watch has a larger retrograde minute hand. During the development of the K.05-0 and K.05-1 calibers, Konstantin Chaykin invented a unique mechanism to drive the moon shadow hemisphere using a planetary gear, which is also used to set the moonphase. The drive of Konstantin Chaykin’s natural moonphase system, which is used in both the Lunokhod and Lunokhod Prime watches, is described as “astronomical”. This means that it is calculated to accurately display the duration of the synodic (lunar) month in 29.53125 days, giving an extremely small margin of error – 0.000622 or one day for 122 years, whereas the moonphase of a conventional design based on a 59-tooth wheel is designed for the error of one day for about 2 years and 7 months. The caliber K.05-1 of the Lunokhod Prime watch was developed by Konstantin Chaykin and is equipped with a natural spherical moonphase indicator. The movement is made entirely in Konstantin Chaykin Manufacture according to the standards of haute horlogerie, using traditional techniques for finishing the components: Côtes de Genève, perlage, fine straight and circular grinding, hand-polished chamfers, engravings, polished screw, pin and jewel recesses, ball polishing of the pivots and rhodium plating. A special feature of the movement is a ‘Pac-Man’ regulator, developed by Konstantin Chaykin for fine adjustment of the hairspring. Caliber: K.05-1, hand-wound, made by Konstantin Chaykin Manufacture Power reserve: 45 hours Functions: – Hour display integrated with day/night indication; – Retrograde minutes; – Natural spherical moonphase indicator. The Lunokhod Prime watch has a very complex shape. In profile it looks trapezoidal, just like the moon rover that inspired it, and the triangular reliefs on the caseband are reminiscent of the moon rover's wheels; similar reliefs can also be found on the crown. The top of the case is spherical, like the Lunokhod moon rover. The case is made of 18k rose gold. Case dimensions: Diameter 47.7 mm; 10.7 mm thick (not including the spherical sapphire crystal over the moonphase indicator).