Perfect Compatibility: YOUSHARES bottle adapter is designed for Stanley 40 oz bottles. It perfectly combines your Stanley 40 oz water bottles to Cirkul flavor cartridges. No Water Leakage: Our water cup adapter is small but precise. After repeated testing, it is ensured that it can effectively maintain the temperature in the bottle without leaking even a drop of water. Food Grade Material: The water bottle transfer adapter is made of BPA-free plastic and food-grade silicone, which is reusable and will not deform, ensuring that every sip of water you drink is clean and safe. Cleaning is Easier: Dishwasher-safe, no hard-to-reach corners, so even hand washing is very easy, stains are easily removed and no odor remains. Easy to Use: Just connect the Stanley 40 oz water bottle to the adapter, insert the Cirkul cartridge, and enjoy ultimate hydration. Compact and lightweight, it is perfect for hydrating anytime, anywhere, whether you are doing outdoor sports, going to work, or traveling.