Primefit IP1414FS-2 1/4-Inch Industrial Steel Plug Set with 1/4-Inch Female NPT, 2-Piece Industrial steel air plug and nipple kit Compatible with industrial, "M", "D" and "I/M" style plugs and couplers Zinc plated steel coupler features high corrosion resistance and long life 1/4-inch body with 1/4-inch female NPT threads Comes with a 1-year limited warranty