Play clock
A play clock, also called a delay-of-game timer, is a countdown clock intended to speed up the pace of the game in gridiron football (American or Canadian). The offensive team must put the ball in play by either snapping the ball during a scrimmage down or kicking the ball during a free kick down before the time expires, or else they will be assessed a 5-yard delay of game (American football) or time count violation (Canadian football; that code's "delay of game" is a different infraction) penalty.