Ultra-complicated Movement ST9100

The ST9100 movement belongs to the category of minute repeater watches, capable of chiming the hours, quarter hours, and minutes. It distinguishes between different times by emitting different tones: low tones for the hours, high tones for the quarter hours, and combinations of high and low tones for the minutes (for example, 3:35 would be indicated by three low tones, two high tones, and five combined high and low tones). The minute repeater function of the watch is primarily generated by the action of the gongs and hammers, which strike to produce different tones for each time indication.