Pressure Washer Adapter Set, 1/4 Inch Quick Disconnect Kit, 5000 PSI by | Jul 24, 20261 pc quick coupler socket: 1/4’’ female NPT thread + 1/4’’ quick disconnect socket. Made of brass. 1 pc quick coupler plug: 1/4’’ plug + 1/4’’ male NPT thread. Made of stainless steel. Easy to connect and disconnect.