SharkBite PEX tubing is a cross-linked polyethylene tubing for a wide range of residential and commercial plumbing applications. Manufactured with an oxygen barrier for radiant floor and hydronic heating applications (available in orange). The oxygen diffusion barrier applied to the exterior limits oxygen permeation through the tubing wall in hydronic heating applications which prevents corrosion of ferrous metal parts in the heating system. Repeating SharkBite imprint pattern provides a visual aid to determine if the tube has been inserted all the way into the SharkBite Push-Fit Fitting. This feature only works if the tubing is cut between the SharkBite imprint pattern. Manufactured to meet or exceed requirements of ASTM F877-2011a and CSA B137.5-2009 & NSF/ANSI 71.