1.1 This specification covers crosslinked polyethylene (PEX) push-fit mechanical fittings for use with crosslinked polyethylene (PEX) tubing in ½, ¾, 1 and 1 This specification covers crosslinked polyethylene (PEX) push-fit mechanical fittings for use with crosslinked polyethylene (PEX) tubing that meet the requirements of Specification F876. These fittings are intended for use in residential and commercial