This ballast is Etelligent? compatible with signal ports for on/off/dimming function. The Sun System? 1 advanced 105 kHz microprocessor is designed specifically to drive DE lamps at sustained peak performance. Sun System? 1 DE series provides premium components and superior construction for the professional horticulture enthusiast. Thermally optimized non-air cooled aluminum housing does not require a cooling fan. Internal ballast programming will protect unit in instance of open circuit, short circuit, over/under voltage or high temperature exposure. Features internal built-in circuit breaker. This Sun System? 1 ballast has dimmable/selectable wattage, turbo and built-in green LED lights for easily identified self-diagnostic performance codes. Low-current, staggered ignition delay feature eliminates circuit inrush overload and protects lamp for increased lumen maintenance. This ballast includes a prewired lamp cord receptacle that is compatible with all Sun System? brand reflectors. Includes a hard-wired 6 ft 277 volt power cord with a L7-15p 277 volt twist lock plug. The Sun System? 1 Etelligent? Controller Kit #902245 (sold separately) allows up to 400 Sun System? 1 ballasts to be daisy-chained together. This controller allows wired control of the on/off/dimming capabilities of Sun System? 1 DE ballast(s). Compliant with both FCC Article 18 Part A (governs commercial use) and FCC Article 18 Part B (governs residential use) as tested by an independent U.S. testing lab in a “true as used” configuration.