Amazon.com: FangKingNo 10PCS 1/2" to 3/4" PVC Reducing Nipple Male Thread to Male Thread Coupling for PVC PIPE Pressure Fittings,PVC Male Adapter for PVC PIPE Connector White (1/2 Inch to 3/4 Inch) :
Charlotte Pipe 2 in. x 3/4 in. PVC Sch. 40 Reducer Bushing Fitting PVC 02108 2600HD - The Home Depot
Value Collection - 3/4 x 1/2″ PVC Pipe Reducing Coupling - 51240976 - MSC Industrial Supply
Lasco 429-422 4 x 3 in. Reducer Coupling Slip x Slip - Pipe Fittings - Amazon.com