New, aluminum reproduction US canteen and cup. These are decent reproductions- but not perfect. The shoulders of the bottle are steeper than the originals, they are 1/2" shorter overall and the cap is tapered slightly. These canteens will fit in an original cup, but an original canteen is a tight fit in the reproduction cup.
Cleaning: We recommend washing all canteens out before use. The best method we've found is to fill the flask about half full with hot water, add a little vinegar, screw the cap on, then shake vigorously for a minute or so. Drain it out, rinse with cold water, and place upside down (a dish rack works well) and allow to dry. Dishwashers will NOT work because the neck of the flask is too narrow for the water to reach the inside.