INCLUDING- Come With 1pcs Female Fitting Male Thread And 1pcs Female Fitting Female Thread And 2pcs Male Fitting Male Thread And 2pcs Male Fitting Female Thread， 6pcs Male Fittings for 6, 8 & 10mm Hose FUNCTION- 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.Zinc Plated Finish For Rust And Corrosion Resistanc SIZE- 1/4" BSP. Tightening 12mm hex (Male fitting Male thread) Tightening 16mm hex (Male fitting Female thread) Tightening 19mm hex (Female fitting Male/Female thread) Type:Male/Female fitting, male/Female thread. 6 x Male Fittings for 6, 8 & 10mm Hose，2 pack per size， Nickel plating is beautiful, can be decorated, the price is high, the process is slightly complicated, the color is silver and yellow. ADVANTAGE- Made of heat treated hardened steel. Spring loaded quick release couplers for use on the compressor side have a valve built in to prevent air escaping while changing between tools.