Magic Corrosion Resistant Check Valve 2 in. 0801-20H The “CR” Back-Flow prevention check valve is completely corrosion resistant, making it the ultimate solution for protecting your expensive Heat Exchangers from the potential damage of inline Chlorinators while also maintaining a Full-Flow circulation system. Numerous features are included with the “CR” Valve including: a proprietary designed Hastelloy® Spring, Glass- Filled Noryl injection molded shaft, 100% Silicone Gasket and a Clear, serviceable lid. The “CR” Valve is also equipped with a ½ lb. spring-loaded gate, allowing it to be installed in any orientation. The package also includes 2 adapters ( 2” Spigot x 11/2” Slip)