ZLT manufactures fire and smoke shut-off devices for ventilation ducts, the FIREPROOF fire-rated duct range, VENTIPIPE lightweight shaft systems and VENTIMAX pressure-differential systems from Jahnsdorf in the Erzgebirge. Its VENTISAFE ASV2 shut-off device against fire and smoke in ventilation ducts to DIN 18017-3 holds DIBt allgemeine bauaufsichtliche Zulassung Z-41.3-700. The company has traded for over twenty-five years.