Canteens, L to R; Two aluminum flasks w/large aluminum cup, steel flask w/bakelite cup, Swedish aluminum flask, NVA.

Original aluminum flask with a large aluminum cup, Heer felt cover and leather strap, bakelite cap.

Enameled steel flask with a bakelite cup, Heer felt cover, aluminum cap.

Swedish aluminum flask, note the large diamater mouth and cap. (Looks OK but the small bakelite cup will not fit over these.)

A couple of things to note about canteens. The cover can be brown or Luftwaffe blue. The best flasks are the aluminum, the steel ones are internally coated with wax to preven rusting and usually foul with rust and 60 years of gunk. Aluminum flasks can be cleaned. I start with boiling water and rinse well, an intermediate wash with muriatic acid, folowed by a thorough rinsing with baking soda. Swedish canteens will give some trouble, they are close but have a much wider mouth so the bakelite cup will not fit over them. NVA (National Volks Armee - East German Army) canteens are not acceptable these are easy to spot, they are cheaply made and have a tapered cup. Invest in a good canteen, you will be carrying and drinking water from it. It gets pretty hot in the field, and good hydration is vital!