The MLC-4 and MLC-4a Master Lighting Controllers are the best devices for controlling up to four H.I.D. lights from one timer. You run 30 amp, 240 volt power into the MLC-4, and all of the outlets are controlled by one 120 volt trigger cord. Plug the trigger cord into a standard timer, and when trigger cord receives power, all of the lights will turn on. The MLC-4 features four standard 240 volt style (NEMA 6-15) outlets to plug in your ballasts. The MLC-4a has 120 volt style (NEMA 5-15) outlets which allows for running your ballasts at 240 volts without having to change out your standard 120 volt ballast power cords. The MLC-4's are rated for 30 amps @ 240 volts.