The FD35GA is a UL555 classified, 1 1/2 hour rated, multiblade fire damper. The FD35GA is an "out of the wall or concrete floor" dynamic rated fire damper with through the "grille access" to the fusible link. The damper can be installed in either supply or return applications and can be installed completely from one-side of the partition (no retaining angles are required on the "back-side"). It features: