Have no fear - the king of all digital ballasts is here! Introducing the Lumatek Dial-A-Watt digital grow light ballast. Operating at either 400 or 600 watts and 120 to 240 volts, this ballast automatically senses the bulb you are using and will operate it to ANSI specifications. Simply insert a metal halide or high pressure sodium lamp, turn the switch to specified bulb wattage, and presto! The ballast will automatically know the bulb type and operate your lamp. Use the Super Lumens feature to boost lamp output up to 10% more light at the flip of a switch. This ballast features an internal resin coating to protect components for long life, and an external breaker system to protect against power surges. Dimmable to 50%, the Lumatek Dial-A-Watt digital ballast is the ideal choice for any serious grower's indoor garden.