The normally open fire door is a fire door release switch added to the equipment with ordinary fire doors, which has the function of preventing the spread of fire and the spread of smoke. Mainly set on the evacuation channel.

https://ztfiredoor.com/25372.html

fire aluminium panel door,fire-proof metal door,дари кисаи оташнишонӣ,fire rated emergency escape door two,fire aluminium door,дари фирор аз сӯхтор ду нуқта,дари кисаи оташнишонӣ,дари металлӣ аз сӯхтор,fire aluminium panel door,fire aluminium door,дари оташ,дари кисаи оташнишонӣ,дари оташнишонӣ,fire aluminium door,дари оташнашаванда,fire aluminium panel door