The ANP T 31 is the common military mask of the French Army. It was in service up to the begening of sixties in French Air Force Troops and in Gendarmerie Regiments

It is an improvement of the ARS 1917. The facepiece is identical , unless the metalic front piece who is of new design with a coupling tube  directed to the bottom and a new flutter exhaust valve.

The seven points head harness is of the same type as on the ARS 17 post war manufacturing , i.e. with spring  straps.

The filter is connected to the mask by means of a 50 cm long rubber corrugated hose.

The common ARS 17 42mm dia is completed by a paper filter against arsine particles, screwed on the main filter

The mask is carried in a bag, either on the shoulder or around the neck

This mask is identical to the common ANP T 31 unless  the mounting of renforced, eyepiece celluloïd glasses and the filter, who is of large shape.

The Bidon Filtrant is a largre filter used by Fortification Artillery  and Engineer troops.

It is composed by a large oval can, containing charcoal and with two paper filter elements against arsine particles. A screwed grid covers allow to change the paper filter devices. 

The most common French Army ANP T 31 at the begening of the WW II It was in service up to the begening of sixties in French Air Force Troops and in Gendarmerie Regiments

 The improvement is due to the new CP 35 filter