Suitable for: Our electronic ballast is designed to power 2 x 36-watt T8 fluorescent tubes Optimized circuit matching design for optimal performance Silent operation for a comfortable environment Energy-saving system for higher light efficiency Non-stroboscopic for eye protection T8 2x36W Wide Voltage Electronic Ballast Direct Start Fluorescent Lamp Energy Saving Reactor Description: An electrical ballast is placed in series with a load to limit the current in an electrical circuit. It's used in fluorescent lamps to limit the current through the tube, which would otherwise reach a destructive level due to the tube's negative differential resistance in its voltage characteristic. Features Electronic Ballast -Color: As shown. -Material: ABS. -Size: 21x3cm / 8.27x1.18 inches. Clockwise rotation normally corresponds to increased pressure; counter-clockwise rotation corresponds to decreased pressure. Package Includes 1 * Electronic Ballast Note: Due to manual measurement, the size may have a 2cm/1 inch error; Due to different screens and angles, the color and size may differ slightly, thank you for your understanding!