The Hydratrak bottle is designed to easily track fluid consumption with elastic bands that you can roll up the tumbler or wear as bracelets each time you refill it. At the end of the day, you can quickly calculate your water intake by counting the bands. They can be rearranged to personalize the tumbler, and they also act as a textured, no-slip grip. Double-wall vacuum insulation keeps drinks cold for up to 23 hours, as well as preventing water rings and condensation. The patented lid design fits tightly to prevent leaks, and includes an integrated soft touch carry ring; you can conveniently store it by slipping the ring over the bottle neck. For drinking comfort, the mouth of the bottle is smooth, with the threads on the inside. The 22-ounce bottle is made of durable, BPA-free stainless steel, and fits in most car cup holders. Hand washing is recommended, do not microwave.