Frick RXB Plus Rotary Screw Compressor, Model/SN XJS120S0935D, Uses either NH3 or R-22 refrigerant. Volume ratio 22-50. This unit directly fits a RXB 39 or RXB 30 Frick screw package for Ammonia or Freon. Unit can be mounted with direct drive on a custom package. Normal capacity uses a 100 hp, 3,550 rpm motor.