SharkBite PEX tubing is a cross-linked polyethylene tubing for a wide range of residential and commercial plumbing applications. The tubing is printed with a SharkBite imprint pattern that 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. The SharkBite tubing with and without oxygen barrier is approved for use in all model codes in the US and Canada for use in hydroid and potable water systems and is certified to the following standards: NSF 14/61, NSF P171, ASTM F 876, ASTM F 877, CSA B137.5 and AWWA C904.