Versions 1221-DOW and 1221-OW are "away from wall" significant efficiency blend fireplace/smoke damper specially suitable for purposes in which the damper can not be put in inside the plane with the wall or floor. They options Nailor’s one of a kind inter-locking double skin airfoil blade design and style that eliminates combustible seals https://dampers-for-industrial-se01223.blogtov.com/17357455/the-smart-trick-of-heavy-duty-stainless-steel-damper-manufacturers-that-no-one-is-discussing