JM cloche

It was a non-retractable non-rotating cupola of steel alloy like GFM cloches, but were armed with twin heavy machine guns, as opposed to the lighter automatic rifles associated with the GFM.

JM is an acronym for Jumelage de Mitrailleuses (twin machine guns).

[1] While the MAC 31 heavy machine guns were of the same caliber (7.5mm) as those in GFM cloches, they had a longer practical range 1,200 metres (3,900 ft) and a maximum range of 4,900 metres (16,100 ft), with a 500 round per minute rate of fire.

It exists in three versions, all designed Model 1930: small, large and two-man.

The blank rear was frequently backed by a concrete-covered embankment, which provided additional cover and reduced the prominence of the cloche.