Umnyango womlilo we-UL ubhekisela kumnyango womlilo ojwayelekile waseMelika, osetshenziswa eNyakatho Melika nakwamanye amazwe nezifunda eziqaphela izindinganiso ze-UL. Ihluke kwezinye iminyango yomlilo, isici esisobala seminyango yomlilo yase-American Standard ukuthi iminyango yomlilo yase-American Standard idinga ukuhlolwa ngesando samanzi omlilo. Siyakwamukela ukuxhumana nathi.

Iminyango yomlilo ye-ZHTdoors, iminyaka engu-31 yesipiliyoni sokukhiqiza eminyango yomlilo kanye neWindows. Iminyango yomlilo eyinhloko ye-UL, iminyango yomlilo ye-EN, iminyango yomlilo ye-BS EN, njll., Sine-certification.ZHTdoors isekela i-OEM kanye ne-design yamahhala.Izinzuzo zethu: ikhwalithi enhle, intengo yefekthri, isevisi enhle.Siyakwamukela ukuthi uxhumane nathi.