The HPR-1 is a hardwired 30 amp capacity, 230 volt version of the UPM-1. The HPR-1 is perfect for controlling higher loads such as large air conditioners or multiple HID ballasts. You supply 240 volt power to the input side of the HPR-1. The air conditioner or ballasts to be controlled are then hard-wired into the output side of the relay. The 16 foot trigger cable coming from the HPR-1 is then connected to your control device such as a time clock, thermostat or environmental controller. When the device applies power to the trigger cable, the relay in the HPR-1 applies power to the connected equipment. The HPR-1 is rated at 30 amps @ 240 volts.