Apollo 1-1/2 in. x 1-1/2 in. PVC Compression Coupling PVCCOMP112 - The Home Depot
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) :