4" 3 Hour Vertical Mount Fire Door 2661-26X26 Commercial 3/16” holes on 1/4” staggered

3/16” holes on 1/4” staggered centers

69% free area * 1308: 7/8" lattice opening

055 T6 aluminum surface mount return air grille * 45 fixed blades parallel to longest dimension * Countersunk mounting holes for flush appearance with color matching Phillips posi-drive screws * Soft White Options * 905 O - recessed screwdriver operated opposed blade damper * No Labor Collar (square sizes only) * 900 T - T-Bar mount * 905 HD - reinforced construction * 905 IS - insect screen * 1335-1338 Series - stainless steel version * Fractional

Minimum size is 4"x4"

Standard collar diameter is the same as the diffuser size

4" 3 Hour Vertical Mount Fire Door 2661-26X26 Commercial 3/16” holes on 1/4” staggeredh3. 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"