Tru-Flate Automotive Quick Coupler Air Hose Fittings 3/8 Body x 1/4 NPT USA MADE | eBay
Air Hose for Pneumatic Tools 1/4 in. Male x 3/8 in. Female Brass Pipe Reducer Coupler Connector Fitting 150 PSI Maximum 1/4 in 18 NPT Home Garage or Professional Shop: Amazon.com: Industrial & Scientific
1/4 In. x 3/8 In. Automotive Series Coupler and Plug Kit 4 Pc
2 Pack 3/8" x 1/4" MNPT Pipe Thread Brass Air Hose Barb Fitting For 3/ – compressor-source