Intermatic timer mechanism for two speed pumps. Fits in any standard Intermatic timer box. When wiring this timer up, one leg of the power is always hot to the pump and the other leg goes through the timer. The timer determines whether the second leg goes to the high speed or low speed terminal of the motor. The motor is always on in low speed until the timer kicks it into high speed. When working on the motor, always turn off the main power switch.