Bellows weight
The bellows plate has a quick coupling for a bellows weight to offset the hydrostatic pressure differences, known as hydrostatic pressure compensation.
Bellows weight is fitted on top of the bellows.
The bellows weight limits the hydrostatic pressure difference that is present at all positions between the respiratory bellows and diver's lungs. The bellows weight also serves as compensation for the IS-MIX's buoyancy.
The bellows weight's compensation for the hydrostatic pressure difference.