QUANTUM 1000 Watt & 600W Digital Dimmable Ballasts for Hydroponics Grow Lights Run at 100%, 75% or 50% power Strike both Metal Halide and High Pressure Sodium Bulbs Accepts 120v or 240v (Both cords included) Allows 50 Hertz to 60 Hertz Runs 15% cooler than other digital ballasts on the market