Products 1221-DOW and 1221-OW are "outside of wall" substantial overall performance mix hearth/smoke damper exclusively made for applications where the damper cannot be put in inside the airplane with the wall or ground. They features Nailor’s exceptional inter-locking double skin airfoil blade style and design that eliminates combustible seals and gives flame and https://heavydutystainlesssteelda12233.laowaiblog.com/35767456/a-review-of-dampers-for-industrial-sector