French Canteen M-1877 - Bidon Français mde 1877

At the start of WWI the Metropolitian troops were using the 1 Litre Modèle 1877 Bidon, which was covered in dark blue cloth while those forces in North Africa were using the 2 Litre Modèle 1877 Bidon which was also covered in a dark blue cloth. 

The French military had thought that 1 liter was enough water to carry while on campaign as they could get re-supplied with water easily but as the war went into trench warfare re-supply became an issue and getting water to the front became difficult so then by 1915 ALL French forces started to get issued the 2 liter version.