UL fireproof doors have been proved to be fireproof tested by the door components in the fire test conducted according to the standards, to ensure their fire performance characteristics as fireproof doors. American standard fire door, wh certificate based on ul standard, with 20-180 minute fire certificate.

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.