Fire doors can be divided into fire doors with and without windows according to whether there are windows on the fire door structure (called windows, which cannot be opened or closed, but only for observation). The glass installed on the fire door cannot be ordinary glass, but must be fireproof glass.

Deriyên agir ZHTdoors, 31 sal ezmûna hilberînê di deriyê agir û pencereyan de. Deriyên agir ên sereke yên UL, deriyên agir EN, deriyên agir BS EN, hwd.. Em xwedî sertîfîkayê ne.