This is a universal volume controller for keyboards, model VP26U by QuikLok. It is designed to work with at least 5 different brands of keyboards on the market today. It uses a custom potentiometer and a polarity switch. The stereo 1/4" cable is 3 feet long and the base is heavily shielded metal. Suitable for use with Yamaha, Roland, Korg, Ensoniq, and Kurzweil electronic keyboards.