Make the connection from PVC pipe to swing pipe for your underground sprinkler system with the 3/4 in. MPT X Spiral Barbed Adapter. Thread the durable fitting onto 3/4 in. female pipe thread (FPT) on one end; twist the other end onto 1/2 in. swing pipe (also known as funny pipe) and it will anchor in place. Fitting is made of acetal plastic treated with UV inhibitors to prevent fading and cracking.