The PVC Compression Ring fits inside a 1/2 in. PVC slip fitting (sold separately) and can be solvent welded to create a leakproof compression adapter. Use to transition from 1/2 in. pipe to 600 Series supply tubing or dripline (0.610 in. to 0.640 in. OD). The green compression ring has an internal barb that compresses the tube to hold it in place. Compression ring is made of PVC and treated with UV inhibitors to prevent fading and cracking.