SharkBite® PEX tubing is a cross-linked polyethylene tubing for a wide range of residential and commercial plumbing applications. SharkBite PEX tubing manufactured without an oxygen barrier is used for potable water systems. SharkBite PEX tubing manufactured with an oxygen barrier is used for radiant floor and hydronic heating applications. It is manufactured with an oxygen diffusion barrier applied to the exterior. It limits oxygen permeation through the tubing wall in hydronic heating applications and prevents corrosion of ferrous metal parts in the heating system. The tubing is printed with a repeating SharkBite imprint pattern that provides a visual aid to determine if the tube has been inserted all the way into the SharkBite push-fit fittings. This feature only works if the tubing is cut between the SharkBite imprint pattern.