Models 1221-DOW and 1221-OW are "outside of wall" superior general performance mixture hearth/smoke damper exclusively made for purposes the place the damper cannot be installed within the aircraft in the wall or flooring. They features Nailor’s special inter-locking double skin airfoil blade design that removes combustible seals and supplies flame and smoke seal https://keeganfwlzo.rimmablog.com/35955939/5-essential-elements-for-dampers-for-industrial-sector