RELIANCE 4.5 SRC - 1/4hp Single Piston Air CompressorThe 1 4hp RELIANCE 4. 5 SRC oil less single piston air compressor is our flagship air compressor and is used in many of our AIRBOOST Mini lake and pond aeration systems. The RELIANCE 4. 5 SRC single piston air compressor has been field proven to outperform many other compressors in both CFM delivered and amp draw while under load. Each RELIANCE 4. 5 SRC air compressor includes [1] high performance canister filter, [4] single stud vibration isolators.