Made of iron material for good sealing performance, rust protection, durability, antistatic, strength and durability. Spring-loaded quick connectors for use on the compressor side have a to shut off the air when you switch tools. Easy to use, just slide the collar back and insert the fitting, then push the collar back completely to lock it in place. Made of heat treated hardened steel. Spring loaded quick release couplers for use on the compressor side have a to prevent air escaping while changing between tools. Features - Color: Silver. - Material: Iron nickel plated. - Size: 4.50 x 2.00 x 2.00cm/ 1.77 x 0.79 x 0.79 inch. - Good sealing performance, rust protection, durability, antistatic, strength and durability. - Used for air tools, air compressor, air nailer, air blow, pressure washer, air hose, etc. - Reduces accidental disconnection. - Male fitting has inside to prevent air escaping whilst changing between tools. - These connectors and fittings enable tools and airlines to be quickly connected and disconnected. Package list: 10 x coupling