Leafy pressure delivery outlet for installing a new staircase in the front room floor, exhaust shaft wall, can also be installed in the exhaust system pipe or duct side end. The main functions and characteristics usually normally closed, electric, manual opening. Output on the start signal. Manual reset closed. 280 ℃ temperature sensor operation, the valve is closed again. The use of thin body, reduce operating box size, increase the effective area of ??the ventilation exhaust.