316 Stainless Steel, 1/2 in x 1/4 in Fitting Pipe Size, Reducing Adapter - 1DFY3|8-4 RA-SS - Grainger
DEWALT Impact Ready 1/4-in to 1/2-in Standard Socket Adapter in the Socket Adapters department at Lowes.com
Proline Series 1/4-in x 1/2-in Threaded Male Adapter Bushing Fitting in the Brass Fittings department at Lowes.com
DCA 2PCS 1/2 inch Square Drive to 1/4 inch Hex Female Socket Adapter Converter Chuck Adapter for Impact Air and Electric Wrench - Amazon.com
Amazon.com: Universal 2.25" ID 2.5" ID Exhaust Pipe Adapter Connector Reducer 304 Stainless Steel 2.25 Inch to 2.5 Inch 2 1/4” ID to 2 1/2” ID kit : Everything Else
DeWALT DW2547IR 1/4 in. Hex Shank to 1/2 in. Socket Adapter (Impact Ready) at Tractor Supply Co.
Amazon.com: KOOTANS 1/2 NPT Male x 1/4 NPT Male Solid Brass Nipples, Heavy Brass Pipe Adapter Fittings Hex Reducing Nipples Connectors 4Pieces : Industrial & Scientific
Impact Socket Adapter Set, PTSLKHN 3 PCS | 1/4", 3/8", 1/2" Drive, Socket Adapter for Drill, 3/8 to 1/2 Socket Adapter, 3/8 to 1/4 Socket Adapter, Adaptation to High Torque Impact Wrenches - Amazon.com
Amazon.com: Universal Vacuum Hose Adapter 2-1/2 Inch to 1-1/4 Inch,1-1/4 Inch to 1-3/8 Inch to 1-1/2 Inch,1-3/8 Inch to 1-1/4 Inch Wet Dry Vacuum Converter Reducer Attachment Adapter kit for Vacuum Cleaner(6pcs) :