Powermate 038-0054PM Pneumatic NPT Female Plug Set, 1/4-Inch, 2-Piece Quickly Connects Air Tool to Air Hose When Used With a Quick Coupler Included In The Set Are Two 1/4-Inch By 1/4-Inch NPT Female Threads, I/M Industrial Series Typically, One Plug Connects a Hose to an Air Compressor, While a Second Plug is Used With a Quick Coupler to Connect a Hose to an Air Tool Manufactured For Use With the Powermate Trademarked QCS System The Quick Connect System Makes Switching Tools a Snap - Just One Hose, One Connection to Operate Multiple Tools