PT Coupling 6026304030CX40A Aluminum Reducer Cam and Groove Hose Fitting, CXA Long Reducer, Stainless Steel 300(HBS) Cam Arms, 3" Coupler x 4" Adapter Reducer changes connection size of cam-locking female coupler Male and female cam and groove connection Aluminum body for corrosion and abrasion resistance and light weight For use with water, hydraulic oil, coolants, gasoline, and petroleum products Complies with Commercial Item Description A-A-59326D for quick disconnect fittings