Amazon.com: 20Pack 1/2 Inch PVC Nipple Male Thread Coupling Adapter Connector (Male x Male) 1/2" PVC NPT Male Thread Coupling Pipe Fitting for Thread plumbing Pipe, Home or Industrial Use, Schedule 40 :
DURA 1/2 in. Schedule 40 PVC Female Adapter Fitting C435-005 - The Home Depot