PVC Pool Parts products are made of hard-shell composites that are unaffected by pool chemicals (chlorine, acid & salt). They are durable, maintenance-free, salt-chlorinator proof and are always cool to the touch. All products are equipped with excellent chemical resistance. Engineered for high strength, the stem incorporates a special shear point to control accidental breakage. Certified by NSF for Potable Water. This means that this valve can greatly divert or converge fluid, regardless of their constitution and temperature. Good chemical resistance. Good abrasion resistance. Good material strength and high impact resistance. Manufactured to tight size and pressure specification.