One must remember (and JFL will back this up) that France also used Hotchkiss guns in the early part of WW I as Aircraft armament, and the flexible strip was developed partly in answer to this need; The Guns used in Aircraft were the Benet-Mercie version (or “Light Hotchkiss”) and calibres were both 8mm Lebel AND .303 British; The British had adopted the Flex. Feed system for their Light Cavalry Hotchkiss Guns (used in Palestine, Mostly), and of course Hotchkiss et Cie. exported its guns all over the world.
As to those particular links shown, it depends where they were found, as to the correct ammo to be placed in them…I think, having the “Hotchkiss” trade name indicates a “private” supply, or contract, rather than Gov’t manufacture…JFL may clarify on this.
Hotchkiss strips, whether fixed or flex, will have Pitch distances according to the cartridge size ( either 8mmLebel, or the “Mauser” size, which included the .303 case as well.)
Compare this flex belt section with a French Standard 24 round Fixed Hotchkiss M1914 strip. If the pitch of the index holes is the same, and the size of the tabs is the same, then it is for 8mm Lebel; if either the pitch (and of course the tabs) are different, then it is most probably a flex belt for .303 (7,7mm for French Airforce)…which used .303 from 1915 till almost the beginning of WWII in Lewis and Darne type aircraft guns.