The Fenwal 12-F27121-000-06 Detect-A-Fire 325°F is a fixed-temperature fire detection device designed to provide dependable protection in HVAC systems. It activates when the ambient temperature reaches 325°F, signaling alarms or initiating control functions for safety response. https://www.partshnc.com/12-f27121-000-06-fenwal-detect-a-fire-325f