4" 3 Hour Vertical Mount Fire Door 2661-36X28 Step Down Ceiling Diffuser Double deflection transition box mount

Double deflection transition box mount spiral pipe grille

Maximum size 60"x48"

115T Series Engineering/Performance Data

Extruded aluminum frame with steel roll formed blades and steel multi-shutter damper

For damper free area chart B click here * 2665 - Round fire door for vertical mount only

4" 3 Hour Vertical Mount Fire Door 2661-36X28 Step Down Ceiling Diffuser Double deflection transition box mounth3. 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"