Commercial steel fire doors can be provided with windows, shutters, ventilation shutters, etc.as required, and the surface treatment is electrostatic spraying.

https://ztfiredoor.com/16406.html

riser door fire rating,single panel fire door,fire rated door self closing,fire safety door price,a rated doors,1 uur gegradeerde muurdeur-gradering,riser door fire rating,brandgegradeerde motorhuisdeur 30 x 80,a rated doors,heat resistant door,single panel fire door,brandbestande skuifdeure,riser door fire rating,glas skuifdeure,single panel fire door,fire rated insulated access door,a rated doors