The STEELMAN 99479 1/4-Inch NPT Brass Coupler Pack is the answer to any workshop or automotive garage that uses multiple tools and air lines. Compatible with Milton or M type fittings, this pack of 10 couplers are constructed of smooth operating brass that surrounds a durable and corrosion / rust resistant zinc plated steel core. The brass slide operates smoothly and the knurled texture provides secure grip even under oily conditions or when wearing gloves. The high flow design incorporates a wider than standard inner diameter that helps deliver more air to pneumatic tools providing you with noticeably increased power and performance. The hex shaped body can be easily tightened with any 11/16-inch end wrench and the threaded female end fits any 1/4-inch NPT threaded fittings.