U.S. Armed Forces GI 5 Quart Collapsible Canteen

These are actual military issue and not the cheap import copy. The canteen can hold up to 5 quarts of water making it very effective if your are going to be out in the field for a long time. They fold up to a very small size for easy storage and can be inflated to be used as an emergency flotation device. Their is a removable mesh screen under the screw down cap to keep larger "floaties" from getting into the canteen while it is being filled from your water source. 

NSN 8465-01-254-5759