Spiral-lock quick couplings has higher safety and stronger resistance to high pressure as the spiral design. It is also one kind of bayonet couplings.Spiral-lock quick couplings have two parts: a plug and a socket. The plug is the male half and the socket is the female half. Combined with the use of environmental humidity conditions, dust conditions, as well as easy to corrosion and other use of the environment, to consider the selection of quick joint type, body material, sealing material. Make sure that the selected quick coupling threads are consistent.Specifications: g1/2,npt 1/4, npt 3/8, g1/4, g3/8, g3/4 and g1.China Quick Couplings manufacturers website:http://www.china-tractorparts.com/quick-couplings/