24Vac Microprocessor based Controller for use with Energy Saver PreCooler & CellCool systems. The MPR-78PC is a basic controller and does not have adjustable "Off" cycle timing or adjustable "On" temperature settings. The MPR-01AW is a more robust controller with "On" temperature settings adjustable from 58 degrees Fahrenheit up to 78 degrees Fahrenheit, adjustable "Off" cycle timings and has the ability to communicate with a hand held programming device. Both controllers require a 24Vac power source and feature sockets for the optional Auto-Freeze protection board.