Styles 1221-DOW and 1221-OW are "out of wall" significant efficiency mix fire/smoke damper specially designed for programs where the damper can't be put in throughout the aircraft of your wall or floor. They characteristics Nailor’s unique inter-locking double skin airfoil blade style and design that eliminates combustible seals and gives flame and smoke https://dampersforindustrialsecto33455.dm-blog.com/37038859/about-dampers-for-industrial-sector