Genuine Hydro Flask custom parts! Small Flex Boot Color: Cascade For 12-24oz bottles. *Please note: Not compatible with 32oz bottles.* Attaching it to the bottom of your bottle protects it from dents, scratches, and dirt if dropped. You can also express your individuality by matching it with your favorite colors. It's also fun to see new colors released every year! It's also exciting that you can't get the previous colors when new ones come out!