Parker 68PMT-10-M16 Push-to-Connect D.O.T. Fitting, Tube to Metric Thread, Brass, Push-to-Connect and Metric Connector, 5/8" and M16X1.5 mm: Amazon.com: Industrial & Scientific
Push to Connect Fittings, Push to Connect Air Line Fittings
Brass Straight Push To Connect Fitting 12 mm OD x - 3/8" BSPT (R) Male - BMTC-Metric x BSPT - Male Straight - Nickel Plated Brass PTC - Push In Fittings
Legris - Push-To-Connect Tube to Metric Thread Tube Fitting: Male Connector, M8 x 1 Thread - 71378897 - MSC Industrial Supply
Legris - Push-To-Connect Tube to Male BSPP & Tube to Metric Thread Tube Fitting: 3/8″ Thread - 02896769 - MSC Industrial Supply