This table top speed control is constructed of heavy duty plastic with durable solid state electronics. It has a dial control for precise speed settings, as well as good repeatability of previous settings. For use with 115 Volt SR, SRB, SRH and SRBH motors. Can also be used with these 115 Volt discontinued motors: Series CC and DD, Series L and LB, Series F, Series PG and 1/8 Horsepower Series S, SB, SR and SRB motors. Dimensions: 6"L x 5"W x 2 1/2"H.