_ Professional manufacturer specializing damper damper installation · 70 ℃ temperature sensor movement, the valve automatically closes. · 280 ℃ temperature sensor operation, the valve automatically closes. · Manually shut down; manual reset open. · Manually adjusting the blade angle. (Five-speed adjustment). · Output signal or interlock control valve closed signal. · Amount of air leakage: the national standard (see test report). · Refractory time: ≥90min. · Corrosion resistance and reliability are in line with the national movement. Features based on user requirements, increased electrical output. Available tension spring instead of weight. Installation should pay attention to the role of the direction of the hammer down.