Uponor AquaPEX red is a PEX-a pipe designed for use in domestic hot water and hot-water recirculation systems. It features full color for easy identification of hot-water lines. The pipe has the highest chlorine resistance rating of 5 and offers 6 months of UV resistance. It is also approved for use in hydronic or radiant heating and cooling applications, however, because the pipe does not have an oxygen-diffusion barrier, it is only appropriate in systems that contain no ferrous corrodible components or where any ferrous components are isolated from the pipe. The PEX-a manufacturing method provides exceptional flexibility, strength, and durability, allowing a bend radius of 6X the pipe diameter to help eliminate unnecessary connections with each change in direction. Also, the pipe elasticity allows it to expand up to 3X its diameter and then shrink back down. This provides exceptional resiliency in freeze/thaw conditions. Note that no piping system is completely freeze proof, but PEX-a provides greater resiliency compared to rigid piping systems. Uponor PEX-a pipe is designed for use with Uponor ProPEX fittings, which require the use of a ProPEX expansion tool and ProPEX rings (sold separately). Material: Cross-Linked Polyethylene (PEX).