A battery reserve indicator on a quartz watch informs the wearer when the battery is low. Often this is indicated by the seconds hand moving at two or three-second intervals. When a Seiko Kinetic needs to be wound, the seconds hand will also move in two second intervals. Most are used to stop and start a stopwatch but sometimes serve other functions. A movement powered by a quartz crystal to.
Quartz crystals are very accurate.
They can be mass produced which makes them less expensive than most mechanical movements which require a higher degree craftsmanship. It is a flat piece of metal, usually shaped like a semicircle, that swivels on a pivot with the motion of the wearer's arm. A crown that can be screwed into the case to make the watch watertight. An additional dial that can be set to the time in another time zone. It lets the wearer keep track of local time and the time in another country simultaneously.