The PowrTrol Temperature Controller is a solid-state, proportional-voltage power control. Even though it is small in size, it provides precise manual control of heating mantles, tapes, cords and other resistive loads. The output range is conveniently adjustable from 5-100% of rated voltage. Supplied with lighted on/off power switch, circuit breaker protection, 3-wire load receptacle, and 3-wire line cord with molded plug. Dimensions: 4"w x 4"d x 3-3/8"h.