When trying to control more than one HID lighting system, you can either use a bunch of timers OR the HPH-4. The HPH-4 makes it simple to control more than one HID lighting system and up to 4000W of lighting from a single timer or controller. Has four universal receptacles that accept either a 120v or 240v male plugs from your HID ballasts. 30A @ 120 / 240v