Stanley Hydraulics 03974 1/2” FNPT Flush-Face Quick Disconnect Coupler Set (Male & Female)Stanley 03974 is a flush face, push to connect hydraulic quick disconnect coupler set for 1 2 FNPT connections. The flush face design helps reduce fluid loss and air inclusion during connect disconnect, and the locking sleeve helps prevent accidental separation. Coupler bodies are steel with zinc plating for corrosion resistance. This set includes both the male plug and female socket and is commonly used with Stanley underwater hydraulic tools.