Magic Plastics 0823-15RTC Check Valve, Magic, 1-1/2" ACME Fine Thd, 1/2lb, ClearCalifornia Residents WARNING: This product can expose you to chemicals including Vinyl Chloride, which is known to the State of California to cause cancer P65Warnings.ca.gov Magic Plastics Retro Smart Check Valve Features: The "Smart" Check is equipped with a 1/2” lb spring-loaded mechanism, allowing the valve to be installed in virtually any orientation. Designed to replace old ACME fine thread style check valves such as Flo-Control without the need for re-plumbing.