Genuine OEM Harman outside temperature kit, part number 1-00-70607. The outside temperature kit is designed for the Absolute 43, Absolute 63, Accentra 52i-TC, Allure 50, P40i-C, P42i-TC, and XXV-TC pellet stove models. The outside temperature kit will increase your overall combustion efficiency and may lower your installation clearances for the exhaust flue. Please see your owners manual for further information.