It is of the same general design as the Army M 33 but has some improvements, the main of them are the internal Tissot vents.

The mask has two exhale valves, each of them located on the sides of the the mask and housed in light alloy moulded casings.

A long dismountable rubber corrugated hose links the mask to the filter with fittings at each ends, allowing to change the hose if necessary.