The Hydrotek LIGHTSPEED FLIP20 can control 20 lights from10 ballasts with up to 10 lights on at a time. Designed to work with ballasts of any voltage, these heavy duty controllers are built to last. 10 balla? The Hydrotek LIGHTSPEED FLIP20 can control 20 lights from10 ballasts with up to 10 lights on at a time. Designed to work with ballasts of any voltage, these heavy duty controllers are built to last. 10 ballast cords on one side and 20 reflector plugs on the other side. Save money by using half as many ballasts!