Hamilton Watch American Classic Jazzmaster Skeleton H42545551. The H 20 S Hamilton automatic movement echoes the skeletonization theme, uniting proven craftsmanship with relentless accuracy. Contemporary decoration, ranging from brushed, skeletonized rotors to an intricate H pattern on individual elements, add a sense of theater to traditional precision timekeeping. The wearer audience participates in this show directly thanks to generously dimensioned openings displaying components such as the escapement, hairspring and barrel zealously at work.