1/4" FNPT A style push type coupler are easy to use; simply push plug into coupler to engage, pull sleeve back to remove. A style couplers have a basic flow size of 1/4" and a maximum air flow of 34 SCFM.
Milton 1/4" FNPT Female Push Type Coupler For A-Body Style Plugs 300 PSI Max 775
Milton 775 777 778 1/4" A-Style Coupler and Plug Set 20 Pieces
Milton 1/4" FNPT Female T-Style Coupler Quick Connect Fitting 300 PSI Max 785
Milton Industries S-213 1/4" NPT 5 Pc A-Style Kit - [1] 775 + [3] 777 + [1] 778
Milton S1758 3/8" Safety Exhaust Coupler, 3/8" FNPT
(1/10)Milton 761-1 1/4" FNPT "V" Style HI-FLOW Steel Plug. Fast, Free S&H