Adventure essential.Make your Hydro Flask your own with a colorful durable silicone Bottle Boot that protects against bumps and dings. Specifically sized to fit our 32 oz and 40 oz Wide Mouth bottles.Fits 32 oz and 40 oz Wide Mouth bottlesMedium boot is not compatible with 32 oz or 40 oz Lightweight Wide Mouth Trail Series bottlesRemovable silicone boot adds extra protection to your Hydro Flask bottle.BPA-FreeDishwasher safeNot for use on a stove in a microwave or freezer.