Uponor, formerly known as Wirsbo, is a leading manufacturer and supplier of Plumbing, Heating/Cooling, and Fire Safety Systems for residential and commercial building applications. The Q4690512 ProPEX Ring with Stop, 1/2" are made from PEX-a material, Uponor ProPEX Rings are required to make a proper ProPEX connection. Includes a leading edge chamfer and stop edge to further simplify the use of ProPEX fittings. Each pack contains (50) ring.