Although the .8 liter capacity M31 Feldflasche (Field Bottle) canteens were the standard issue canteen, field medics (Sanitäter) and medical personnel were issued a larger, one and a half to two liter capacity canteen that was based on the larger canteens used by their WWI counterparts. These larger medical canteens, called Labeflasche (refreshment bottle), were of identical design to the standard M31 canteens but came equipped with a different carrying harness and shoulder strap assembly. They were also utilized by Gebirgsjäger (Mountain Troopers) during the war.
Originally the mountain troops/medical canteens were manufactured in aluminum but later as the aluminum was required for other more critically essential items the canteens began to be manufactured in steel. With potable fluids being such an essential item for an individuals well-being the mountain troops/medical canteen must be considered as a very important piece of kit.