4 Piece 1/4 inch x 3/8 inch Automotive Coupler and Plug Kit 150 PSI Automotive series Brass coupler, steel plugs 150 PSI maximum Includes: (1) 3/8" T x 1/4"NPTF brass coupler, (1) 3/8" T x 1/4"NPTF steel plug Includes: (2) 3/8" T x 1/4"NPTM steel plugs