Kaishan KRSD single-stage direct drive compressor line is one of our most popular lines of compressors. TheseKRSD compressors utilize rotary air compressor technology to deliver a constant stream of compressed air where and when you need it most. This air compressor type uses helical screws in a continuous motion to reduce the volume and maximize the pressure of incoming air. Precision machining and proprietary bearing design within the industrial rotary screw air compressor airend hold the male and female screws, or rotors, in precise alignment.