CRAFTSMAN 3/8-in to 1/2-in Standard Socket Adapter in the Socket Adapters department at Lowes.com
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
Everbilt 3/8 in. Flare x 1/2 in. MIP Brass Adapter Fitting 801269 - The Home Depot
PROFLO® 3/8 x 1/2 in. Sweat x Compression Brass Adapter - B14XR - Ferguson