Circline fluorescent lamps are circular in shape, allowing them to concentrate light in a small area and to fill a room with uniform light. These lamps are used in many residential applications and require a ballast to operate. Fluorescent light ballasts regulate the current flowing into the lamp while providing the lamp with sufficient voltage to start.
If you are looking for a circline ballast, look no further than Bulbs.com. We have a number of choices for T9, T8 and T12 lamps. You will be sure to find the right ballast for your application.