The spectrum of their use is vast. Generally speaking, these models will be useful anywhere where it is required to remove or, on the contrary, supply very hot air. (Small outdoors grills, heating equipment for premises like fireplaces and furnaces, hot workshops etc.) 
VO-T series fans are designed for installation on air ducts with the following cross-sections: Ø90, Ø96, Ø100, Ø120, Ø135, and Ø150.
VOK-T series fans are designed for installation on air ducts with the following cross-sections: Ø100, Ø110, Ø120, Ø135 и Ø150.
The fans are equipped with an in-built noiseless and hermetically sealed electric engine including two-capsule bearings produced by a Japanese company, NSK, which is guaranteed to work for 30000 hours without any flows if installed horizontally or vertically. The level of protection of in-built electric engine — IP 44 — allows the fan to work normally under the conditions of high humidity.
The enclosure, the turbine, and the check valve are made of aluminium alloy or glass-nylon composite, which guarantees effective cooling and better fire safety. 
Duct fans of VO-T, VOK-T and VK series are made of high quality and non-toxic materials; they meet fire safety standards.
It is possible to equip the fans of VOK-T series with a check valve.