The STEELMAN 99473-B 1/4-Inch NPT Solid Brass Coupler Pack is the solution for any workshop or automotive garage that uses multiple tools and air lines. Compatible with Milton or M-type fittings, this pack includes ten couplers and ten plugs that enable you to prep air tools and lines before work starts. Both feature a high-flow design that incorporates a wider-than-standard inner diameter that delivers more air to pneumatic tools and provides you with noticeably increased power and performance. The couplers' hex-shaped body easily tightens with any 11/16-inch end wrench, and the threaded female ends fit any 1/4-inch NPT threaded fittings. The plugs feature a hex section that fits a 14mm wrench and has 1/4-inch male NPT threads.