The elastic bands make it easy to track fluid consumption; wear them as bracelets or roll them up the tumbler each time you refill it. At the end of the day, you can quickly calculate your water intake by counting the number of 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, as well as preventing water rings and condensation. The press-in lid has a silicone gasket, so it stays in place, and a built-in tab for easy removal. The straw is wide and easy to clean, great for shakes and smoothies, or you can drink directly from the lid and slide it closed to prevent splashes while traveling. The 20-ounce bottle is made of durable, BPA-free stainless steel, and fits in most car cup holders. Hand washing is recommended; do not microwave.