Interstate Pneumatics CPA681 3/8 Inch Automotive Steel Coupler Plug x 1/2 Inch Male NPT 3/8 inch Automotive Steel Coupler Plug x 1/2 inch Male NPT Body: Forged tool steel, heat treated and zinc plated Plug Body: 3/8 inch Type: Automotive (Tru-Flate) Threads: 1/2 inch NPT Male