4pcs Male Air Line Hose Fittings Zinc plated finish for rust and corrosion resistance Easy to use, just slide back the collar and insert the fitting, then slide the collar fully back to lock in place Spring loaded quick release couplers for use on the compressor side have a valve built in to shut off the air when changing between tools Used for air tools, air compressor, air nailer, air blow gun, pressure washer, air hose, etc, Manufacturer: BE-TOOL