1/2 lb. spring "magically" eliminated water hammer Reduces motor and pump noise from plumbing system Designed for both horizontal and vertical usage Full flow, non-clog design installation Durably constructed PVC check body and compression end fittings Solvent weld ends with unions allow for easy installation. No threading of pipe required Pressure rated at 50 PSI (115 ft) Consult factory if use over 130° F required Suitable for installation below basin cover