4" 3 Hour Vertical Mount Fire Door 2661-28X28 Residential Registers & Grilles * 2634 - Square or

* 2634 - Square or rectangular Spring actuated (6) out-of-airstream fire damper for horizontal or vertical mount

3 or 4 way patterns * Spring push release for easy access to adjust pattern controllers * Round No Labor Collar sizes: 6-10"

Options * MAR - Mounting Angle Ring (sold in pairs - 2 needed

375 Series Engineering/Performance Data

Stainless steel

4" 3 Hour Vertical Mount Fire Door 2661-28X28 Residential Registers & Grilles * 2634 - Square orh3. 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"