Forney 75137 Pressure Washer Accessories, Quick Coupler Plug, 3/8-Inch Female NPT, 4,200 PSI Used in combination with the quick couplers and are used anywhere high pressure connections are frequently assembled and disassembled Ideal for quick exchange of spray nozzles and spray guns These quick couplers plugs connect to all of the most common pressure washer equipment They connect to male or female fitting threads in 1/4 and 3/8-Inch sizes