Milton 1/4" Male NPT A style coupler has a push type design to quickly connect coupler; simply push plug into coupler to engage, pull sleeve back to remove. Must have air fitting kit for air tools, air compressor, air nailer, air blow gun, pressure washer and air hose.Accepts the following Milton A style plugs - #778, #777, #777-4, #777-6, #1777-4 and #1777-6.