"Primitive" silent compressor. Our JUN-AIR oil-lubricated compressors are widely trusted in the * range, with many units still operating after 25 years - a testament to the quality and reliability of the JUN-AIR compressors. Contrary to conventional compressors, our JUN-AIR compressors do not provide piston rings. Instead, the tolerance between piston and cylinder has been reduced, thus minimizing heat generation and energy loss.