C.A.P. MLC-8 and MLC-8a master lighting controllers 

The C.A.P. MLC-8 and MLC-8a master lighting controllers allow you to control up to EIGHT 1000 watt HID lights from one 40 amp, 240 volt power source from one time-clock or controller. Run 40 amp, 240 volt power into the MLC-8 or MLC-8a, and all of the outlets are controlled by one 120 volt "trigger cable". The trigger cable can be plugged into a standard 24 hour timer or lighting controller. 

The MLC-8 features eight standard 240 volt style (NEMA 6-15) outlets, which your ballasts are plugged into. The MLC-8a uses 120 volt style (NEMA 5-15) outlets which allows for running your ballasts at 240 volts without having to change out your ballast power cords.

These light controllers need to be hardwired. We recommend a licensed electrician install this unit.

Specifications:

Trigger Voltage: 120 volts
Receptacle Type: MLC-8: Nema 6-15 /// MLC-8a: Nema 5-15
Main Power Voltage: 240 volts
Maximum Relay Amperage: 40 amps
Maximum Wattage: 8000 watts/1000 watts per receptacle
Operating Temperature Range: 32-120° F
Operating Humidity Range: 0-99% RH
Relay Operations (minimum): 100,000 Electrical

Warranted against defects in workmanship and parts for THREE Years!

More info from the Manufacturer (PDF format - Lots of detail.)