1994 Frick Micro Control Panel. Model: RWB II Plus. Serial number: 209503. System requirements: 120 V, 25 amps, 50/60 Hz, single phase. Calibrated for refrigerant: R-717. The RWB II Plus offers continuous monitoring of the compressor unit’s condition and operation, directing instructions to various unit subsystems via its membrane keyboard. In addition to the keyboard, there is an emergency stop button that will bypass the computer and remove all power from the outputs when toggled, shutting down the compressor motor and all high voltage to the compressor auxiliary systems such as the oil pump and liquid injection solenoid. An additional safety feature of the microprocessor is an output watchdog circuit, disabling (turning off) all outputs if the microprocessor should fail. Overall dimensions: 28 in. L x 11 in. W x 28 in. H.