Suitable for M or D type couplers, interchangeable/compatible with most manufacturers.Industrial Type D 1/4 inch Quick and easy connect system, optimal sealing and high efficiency High quality brass durable, no rust, more wear resistant than aluminum Package Includes: 10 Pcs Female Plugs, Recommended use with Thread Seal Tape (Teflon tape) Common Use to air fitting kit for air tools, air compressor, air nailer, air blow gun, pressure washer, air hose