Steel fire door closers, sequencers, hinges and other easily worn accessories are high-quality hardware, and the use times are strictly tested to ensure the service life of the product. The steel fireproof door has a good airtightness, which is closed in place and tightly, and will not leave a crack in the door to cause the indoor air conditioner and heater to overflow.

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.