The California Air Tools 60040CAD Ultra Quiet and Oil-Free Air Compressor is designed to be 1 of the quietest 4.0 HP air compressors in the industry having only 75 dB of sound. The Powerful two 2.0 HP motors operates at only 1680 RPM creating less noise and less wear. The New SP Series of Ultra Quiet Air Compressor Motors have been designed to increase duty cycle and allow for longer continuous run times. The Oil-Free Dual Piston Pump System is engineered for high performance and durability. The CAT-60040CAD Air Compressor has a Oil-Free Dual Piston pump designed to have a life cycle before wear of 3000 Plus hours compared to other comparable air compressors with life cycles of 1500-hours or less. The Oil-Free pump allows for use in a variety of temperatures (cold starts) and uneven terrains (no oil in the pump). The large 60 Gal. Steel ASME Air Tank is just the right size for shop or garage. Designed for the person looking for Power, Air Flow and Less Service with at Least 30% Less Noise.