This 1/4 INDUSTRIAL (I/M Style) kit contains five pieces, three male quick couplers, one male plug & a triple outlet manifold. The assembly is ideal to connect three air tools to a single air hose. With its manual connection, the quick coupler has a simple usage. To connect or disconnect the plug from the coupler, all you need to do is activate the socket manually. Its connection is efficient & secure with the internal four-ball locking mechanism. The sleeve guard helps prevent accidental disconnections of the coupler. As for your plug & coupler, they have a hardened surface by heat treatment & zinc plated for better quality & higher corrosion resistance.