Amazon.com: CEKER 1/4 Push to Connect Air Fittings 1/4 Inch Tubing Od to 1/8" NPT Male Thread Air Line Quick Connect Fitting Pneumatic Fittings Push In Connectors Air Hose Fittings 10Packs :
Amazon.com: TAILONZ PNEUMATIC 1/4 Inch OD Copper Nickel Plating Straight Union Connect air Fittings Quick Connect Push Lock Fittings Pneumatic Fittings Tube connectors PU-1/4 (Pack of 10) : Industrial & Scientific
Amazon.com: PROCURU 10-Pack 3/4-Inch Pushfit Tee, Push-to-Connect Brass Plumbing Fitting for Copper, PEX, CPVC, PE-RT Pipe (8X7014-10P) : Everything Else
SUPPLY GIANT CNSD3344 1-1/2 X 3/4 Black Malleable Iron Reducing Coupling, 1-1/2 in. x 3/4 : Everything Else - Amazon.com