This controller was designed to control AC motors with carbon brushes, anything from drills to vacuum cleaners to saws. Unlike normal dimmers there is a phase-cut only once per period. The moment of cutting determines the speed, which can be adjusted from 5-95%. Thanks to this control, this kit provides high torque even at low speeds! Not just for 110VAC and 220VAC motors, this kit can also be used for low voltage (24VAC) AC motor loads. The supply and load circuits are electrically isolated from each other for both safety and reliability. Unlike a lot of AC controllers, RFI is suppressed to eliminate noise and interference. AC power input is 110-240VAC. Load voltage is 24-240VAC. Measures 5.1" x 3.0". From Velleman.