The 'Jumping Hour Watch' by Jaipur Watch Company, is a unique timepiece with a "hour window" instead of a "hour hand"!
Instead of the hour hand sweeping the dial like a traditional timepiece, a disc hidden behind a tiny window on the dial 'jumps' to accurately display the hour when its minute hand reaches 12 instead (60 minutes). A 42-hour power reserve is provided by a modified automatic movement.
The hour window is located at the very top of the enamelled off-white dial of this heirloom. It has a large minute hand that sweeps the dial, and a smaller second hand on a subdial. The regulation of power transfer to the hour disc is part of the difficulty of creating a jump hour movement.