3 Hour Out Of Air Fire Door Grille 2663-44X44 Residential Registers & Grilles Nylon bushings on adjustable blades

Nylon bushings on adjustable blades prevent metal on metal rattle

Access door with 1-3/8" deep steel roll formed frame

52h * Interlocking steel roll-formed blade (3) with roll-formed frames (1) * Blade lock (5) * Damper manufactured from corrosion tested galvanized mild steel (G-90) * Self locking corner (4) * 165° replaceable fusible link (2) h3

CB20 - two way

22 gauge galvanized steel roll formed frame

3 Hour Out Of Air Fire Door Grille 2663-44X44 Residential Registers & Grilles Nylon bushings on adjustable bladesh3. Standard Features * 2661 Square or rectangular fire door for vertical mount only. Maximum dimension 60x60. For damper free area chart A click here * 2663 Out of Airstream fire door. Square or rectangular for vertical mount only. Maximum dimension 60w x 52h. For damper free area chart B click here * 2665 Round fire door for vertical mount only. Available 4" thru 52" round. * 3 hour rated * UL and California State Fire Marshall approved * 4 1 4"