Plug Connector, Plug push in fitting, Tubing Stopper
Nylon Plug, 3/8″ | Tramec Sloan
Air Hose Fittings,1/4 Inch NPT Male Plug, Industrial Air Coupler Plug, Pneumatic Air Plug Kit ,Air Compressor Quick Connect (1/4'' FP-NPT) - Walmart.com
Pneumatic Plug Connector Tube OD 3/16" Plug In Air Tube Fitting 10 Pieces | eBay