These products are fire protection and Smoke dampers produced by Quanda. They are mainly used to block smoke and flame from the fire area. They provide stability and are integral to the fire-resistance for a specific period of time. The damper produced by Quanda features improved air tightness and optimized flexibility. At present, the reasonable setting of this kind of products in ventilation, air-condition, smoke prevention and exhaust plays an important role in firefighting.