Normally a mechanical timer or light control box (without battery backup) stops when power is lost and restarts from the same (time) position once power is restored. To prevent a grow cycle time getting distorted against real time, the timer or light control box needs to be prevented from automatically starting. The Timer Reset Box does this by preventing power from the box from restoring until the reset button is pressed. This gives the grower the opportunity to make adjustments if necessary before the cycle is restarted. Maximum 7.5 amp output. Not to be used for boxes with one common cord for both timer and sockets.