The normally open fire door should be used for the fire door set in the building where people often pass.

https://ztfiredoor.com/26932.html

residential fire rated doors,protipožiarne dvere,požiarny uzáver,Protipožiarne dvere 20 minút,fire resistant door,fire door price,residential fire rated doors,fire rated door,fire rated garage door,protipožiarne dvere,90 minute fire rated doors,fire door,Protipožiarne dvere 20 minút,fd30 door,sliding fire doors,residential fire rated doors,6 panel fire door,steel fire door,protipožiarne dvere,fire rated access panel,Protipožiarne dvere 20 minút,fire rated access doors