The Siemens Building Technology 333-572 High Temperature Diaphragm No. 6 (5-Pack) is a precision replacement diaphragm set designed for use in high-temperature pneumatic control valves within HVAC systems. Each diaphragm flexes responsively to pressure changes, enabling accurate modulation of steam, hot water, or air flow in commercial heating and cooling applications. https://www.partshnc.com/hi-temp-6-diaphragm-5-pack