This series serves as a replacement for the 30K-4 type axial fan. The BT35 model is designed for ventilation in environments containing flammable, explosive, or corrosive gases. The T35 model, on the other hand, is intended for ventilation and cooling in factories, offices, residential buildings, and similar settings. It can also be installed in series within longer pipelines to increase internal air pressure. The air being moved must be non-corrosive and free of significant dust, with a temperature not exceeding 50°C.