This high quality Hydroflask Boot by Rapt is made of flexible, ergonomic silicone to protect 18oz, 24oz, 32oz or 40oz Hydroflasks from dings, dents and scratches in a beautiful, eye-catching way. It is made from food-grade, non-toxic, BPA-free silicone for those looking for peace of mind when using Hydro Flask accessories. The silicone cover is built with functionality, aesthetics and stability in mind. It is a perfect gift for athletes, busy parents, coworkers, sufferers of arthritis, hikers, etc.