Types 1221-DOW and 1221-OW are "outside of wall" significant efficiency combination fire/smoke damper exclusively created for purposes where the damper can not be mounted inside the airplane on the wall or floor. They capabilities Nailor’s distinctive inter-locking double pores and skin airfoil blade design that removes combustible seals and presents flame and smoke https://heavydutystainlesssteelda57990.p2blogs.com/35550073/a-review-of-heavy-duty-stainless-steel-damper-manufacturers