Description SharkBite Max check valves are spring-loaded and designed to prevent the reverse flow of water. Max check valves can be installed horizontally or vertically. Compatible with PEX, copper, CPVC, PE-RT or HDPE SDR-9 in any combination, Max check valves are ideal for working in tight spaces and can be rotated after assembly. WARNING: This product can expose you to chemicals including Lead which is known to the State of California to cause cancer, birth defects or reproductive harm and Butyl Benzyl phthalate (BBP) which is known to the State of California to cause birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov