American Standard, 051091-0070A, Pressure Balance Cartridge, For Use With: Reliant + Bath/Shower, Plastic, Import

This Pressure Balance Unit maintains a constant output temperature in response to changes in hot and cold water supply pressure. This means there's less chance you'll experience dramatic changes in water temperature. The diaphragm system with integrated check valves is engineered to eliminate cross flow and this Pressure Balance Unit is also designed to avoid failure due to mineral deposits, so it is ideal for use in hard water areas.