1/2 to 3/8 Reducer Faucet Adapter - Compression Brass Pipe Fitting, 3/8 Male to 1/2 Male Supply Line Adapter for RV Kitchen Plumbing, Water Hose Pipe Connector with Rubber Washer, (2 Pack) - - Amazon.com
PlumbPro 3/8 in. x 1/2 in. Brass Flare x Male Adapter 00512 - The Home Depot
3/8" x 1/2" Male Reducing Connector | Air Pneumatic Fittings & Adapters