Amazon.com: SNS SPU-5/16 5/16" Tube OD Plastic Straight Union Pipe Tube Fitting Straight Pneumatic Connector(10 PCS) : Industrial & Scientific
PC5/16-N1 - (5/16 Tube x 1/8" Male NPT, 10 Pack) - Advanced Technology Products
JEGS 110558: -6 AN Male to 5/16 in. Tube Fitting Black - JEGS
Amazon.com: TAILONZ PNEUMATIC 304 Stainless Steel Male Elbow - 5/16 Inch Tube OD x 1/4 Inch NPT Thread 90 Push to Connect Tube Fitting PL-5/16-N2 (Pack of 2) : Industrial & Scientific