1. Its air tightness passed rigorous smoke isolation test in the close state；
2. It can be linked with the fan motor to realize zero wind resistance operation in the fully open state ；
3. Strong pressure resistance, can long-term bear strong wind making by high negative pressure fan without deformation；
4. High-strength plastic coupling and aluminum alloy body, with anti-corrosion to be adapted to all kinds of harsh animal husbandry environment, or marine environment.
5. When reaches the positioning, the motor power is cut off and self-locking
6. Material: Aluminum alloy frame + PVC shutter piece + coated steel bracket.
7. Motor data:
Volts: 220V/50HZ (special volts is available)
Operation time consuming: full open 19 seconds, full closed 19 seconds
8. Overall dimensions: 1490*1715*255mm (special size is available)