What is a watch minute repeater?

A minute repeater is a mechanical complication in a watch that strikes the time with the push of a side button. Typically, the tones are lower for the hours, a two-tone for the quarter hours and higher tones for the minute. You can find watches, pocket watches and wristwatches with minute repeaters from the early 1900s and mid-19th centuries on 1stDibs.