To explain how the movement works I want to quote Michael Friedberg, because it’s difficult to explain: ‘This movement used the now famous Pellaton winding system, in which rollers (shown at left in red) oscillate between an eccentric cam, which causes two clicks (shown in yellow) to ratchet against a saw-toothed winding wheel. The system had many advantages: it was easy to disassemble for service and it offered shock resistance. It also was efficient in winding, both because of the ingenious design and because two jewels could be used as bearings due to the shock resistance. While the mechanism was unique to IWC and patented, its concepts had antecedents’.