Uxcell Compression Coupling 8mm x 8mm Tube OD Compression Union Pipe Fittings Blue 2 Pack - Walmart.com
8mm x 1/4'' NPT 90deg Elbow Push-in Fitting with Male Threads Stainless Steel FKM Rotatable | Tameson.com
8mm x 1/4'' NPT Push-in Fitting with Female Threads POM EPDM [5 Pieces] | Tameson.com
Amazon.com: 8mm Tubing OD Air Fittings Push to Connect Fittings 1/4 Inch NPT Pneumatic Fitting Push in Connector,CEKER 1/4 NPT Male Air Line Fittings Quick Connect Air Hose Fittings for 3D Printer