When trying to control more than one HID lighting system, you can either use a bunch of timers OR the HPH-8. The HPH-8 makes it simple to control up to 8000 watts of lighting from a single timer or controller. The HPH-4 has EIGHT UNIVERSAL receptacles that accept either a 120-volt or 240-volt male plugs from your HID ballasts. 50-amps @ 120 / 240-volt