The double-wall vacuum-insulated walls give you a worry-free mind knowing your favorite beverages are kept icy cold or piping hot for hours.  Made of lightweight 18/8 food-grade stainless steel that is non-leaching and will not retain taste or odor. The double-wall technology prevents condensation on the outside on those hot sunny days while keeping the heat within the inner wall so you don't have to worry about burning your hand, much like a metal water bottle. The 21oz bottle water is the optimal size to use as your everyday water bottle and is designed to fit in your backpack and most car cup holders with its narrow bottle design. The vacuum-insulated walls ensure when you fill it with your ice-cold water in the morning it will last until your next refill; ideal for a cycling water bottle. The double-wall technology prevents sweating on the outside of the bottle, so you don't have to worry about it slipping out of your hand on your afternoon run. Includes a standard mouth leak-proof straw cap with silicone ring to ensure a snug fit to the top of the bottle to retain your beverages' optimal temperature and act as an insulated coffee mug; easily removable for proper cleaning. The lid is made to screw off and on your bottle easily. A great way to reduce your carbon footprint and keep you going no matter the adventure!