: 18/8 food-grade stainless steel is the standard for durability and preventing flavor transfer. If you have a sensitive palate, consider a glass-lined option like the Purist Mover Go to product viewer dialog for this item.
Based on expert testing and user reviews, these are the standout models currently available: Flask Category Recommended Product Highlights Hydro Flask 40 oz Wide Mouth Go to product viewer dialog for this item. Daily Hydration where to buy a good flask
: "Double-wall vacuum insulation" is essential if you want to keep drinks cold for 24+ hours or hot for 12+ hours. : 18/8 food-grade stainless steel is the standard