PVC Back Draught Shutters VK-B
Back draught shutters for air exhaust in any type of installation. The frame is made out of aluminum and the blades - PVC, the color is gray - RAL 7015. The blades open when exposed to overpressure. This happens when the pressure is 20 Pa for air speed of 2 m/s, 25 Pa for air speed of 3 m/s and 30 Pa for air speed of 4 m/s.