Amazon.com: 12mm Quick Fitting, 1/2” OD Push to Connect Pipe Tube Straight Fittings, Pneumatic Air Line Connector 20Pcs (PU12) : Industrial & Scientific
Source Air Pneumatic Connection 12mm 1/4 inch 1/4" Male Straight Pu Hose Plastic Pipe Fitting PC12-02 One Touch Plastic Pipe Connector on m.alibaba.com
Amazon.com: Metalwork Plastic Push to Connect Straight Union Pipe Tube Reducer Fitting, 12mm OD x 10mm OD, Reducing Coupler Straight Pneumatic Connector (Pack of 10) : Industrial & Scientific
Brass Hose Barb Fitting,Connector,12mm Barb x G1/4 Male Pipe Adapter - Gold Tone - 1/4" G x 12mm - Bed Bath & Beyond - 27578899
Air Pneumatic 10mm 8mm 12mm 6mm 4mm Hose Tube 1/4''BSP 1/2'' 1/8'' 3/8'' Male Thread Air Pipe Connector Quick Coupling Brass Fitting,PC10-01: Amazon.com: Industrial & Scientific
12mm x 13mm Plug-in Fitting with Hose Pillar Brass FKM [2 Pieces] | Tameson.com
Uxcell 12mm Barbed x 25mm OD Spigot Straight PVC Pipe Fitting Quick Connector, Blue 2 Pack - Walmart.com