Filter and ventilation unit

FVU (Filter-ventilation unit) supply and exhaust ventilation. The air is sucked in from the outside, passes through the filters (visible on the left) and an excess pressure is created inside the bunker, which does not allow dirty air from the outside to get inside. At the same time, through special hoses, powder gases are sucked out of the machine gun body and the box for spent cartridges. The unit is fully operational.