Tekmar Controls 054 Room Temperature Unit 40–100°F is a temperature sensing and monitoring device designed to provide accurate indoor temperature feedback for compatible HVAC control systems. It works by measuring room temperature within a 40–100°F range and sending precise signals to the system controller, allowing efficient regulation of heating and cooling equipment. https://www.partshnc.com/054-tekmar-controls-room-temperature-unit-40-100f