Different size PVC concentric reducer,pipe reducer for spa and bathtub piping system - AliExpress
PVC Pipe Reducer, Packaging Type: Box, Size: 20 mm to 315 mm (1/2 inch to
Amazon.com: FangKingNo 10pcs 3/4" to 1" PVC Reducing Female to Female Threaded Coupling for PVC PIPE Pressure Fittings ,PVC Reducer Female Adapter for PVC PIPE Connector White (1 Inch to 3/4 Inch) :
PVC Schedule 40, Clear, Reducer Bushing, Socket x Socket, 3/4 in. to 8