- The most widespread are the GFM cloches, where GFM means Guetteur fusil-mitrailleur (machine-gun sentry). They are composed of 3 to 4 openings, called crenels or embrasures. These crenels may be equipped as follows: Rifle machine-gun, direct vision block, binoculars block or 50 mm (2.0 in) mortar. Sometimes, the cloche is topped by a periscope. There are 1,118 GFM cloches on the line. Almost every block, casemate and shelter is topped by one or two GFM cloches.
- The JM cloches are the same as the GFM cloches except that they have one opening equipped with a pair of machine-guns. There are 174 JM cloches on the line.
- There are 72 AM cloches (armes mixtes or "mixed weapons") on the line, equipped with a pair of machine guns and a 25 mm (1.0 in) anti-tank gun. Some GFM cloches were transformed into AM cloches in 1934. (The aforementioned total does not include these modified cloches.)
- There are 75 LG cloches (lance-grenade – grenade launcher) on the line. Those cloches are almost completely covered by concrete, with only a small hole through which grenades were launched for local defence.
- There are 20 VP cloches (periscopic vision) on the line. These cloches could be equipped with several different periscopes. Like the LG cloches, they were almost completely covered by concrete.
- The VDP cloches (direct and periscopic vision) are similar to the VP cloches, but have two or three openings to provide a direct view. Consequently, they were not covered by concrete.
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