The problem with a lot of flasks is at the end of the day they're just too flimsy for any real activity; easily dented, or the caps stop screwing on properly, leaving you thirsty at critical moments.
Nix that with High Camp's Firelight Flask 750, which is every bit as rugged as it sounds. The stainless steel beast has a leakproof seal and is made to withstand anything you or the great outdoors can throw at it.
The best part, however, besides the fact that it just went on sale, is the built-in tumblers, also crafted of steel and like the container itself are double-wall vacuum-insulated, so you don't have to swig from the flask itself like some kind of savage. Plus they magnetically attach to the flask so there's no danger of them going astray.
The 750 ml size will fit a whole fifth of Scotch if you so inclined. The ultimate flask in other words. And if you don't use it for anything stronger than coffee we won't tell.