This two-pieces ARO 210 (A Style) contains a quick coupler & plug assembly. This kit is ideal for a tool connection, i.e. for connecting a tool to an air hose. With its manual connection, the Maxquik 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, it has a hardened surface by heat treatment & zinc plated for better quality & higher corrosion resistance.