COMPATIBILITY - Our Silicone boot ONLY fits Hydro Flask Water Bottles 32 40 oz(Note: it is not compatible with 30-40oz Stanley flask with thinner bottom) HIGH QUALITY MATERIAL - Made of food-grade silicone, soft and durable, more elastic, will not be deformed, BPA free, safe for children. Easy to use, easy to clean, reusable. It is safe to take it as a dog bowl on-the-go activities MAXIMUM PROTECTION - This durable bottom sleeve helps protect against dents, dings, and damage. Give your cup and tumbler a longer life. It's the perfect cup tumbler accessory for your active, on-the-go lifestyle SIMPLE DESIGN - Simple solid color design, very versatile for your various colors of cups. Warning: silicone boot only, flask water bottle is excluded BETTER SERVICE- Any questions, please contact us, we will reply within 10 minutes during working time Soledea Silicone Sleeve Boot for 32oz 40oz Hydro Flask, Wide Mouth Water Bottle Boot Bottom Base for Hydro Flask 32oz 40oz Only