The Legacy Mfg. Flexzilla Pro High Flow Couplers and Plugs, designed to increase the amount of air flow to the air tool, feature a push-to-connect system making connecting simple. These couplers and plugs are ideal for spray guns, impact tools or high-output tools. These Flexzilla Pro High Flow fittings should be connected from the tool, all the way to the compressor for the best performance an air system can provide, says the company.