Brand New Tumbler Adapter for Stanley to Flavor Cartridges, Use Your Flavor Cartridges Perfect Compatibility - Ensure a perfect fit with the Adapter for 30oz / 20oz Stanley QUENCHER Tumbler to flavor cartridges. Our precision-engineered design seamlessly connects your 30oz / 20oz tumbler cup with flavor cartridges, allowing you to enjoy the best of both worlds effortlessly. Portable & Convenient & BPA free - Take your favorite flavors anywhere with this Stanley Cup Adapter Perfect for the office, gym, or outdoor adventures. Easy to Use - Experience hassle-free hydration, simply attach the adapter to your tumbler cup, then insert the flavor cartridge, and enjoy your customized drink in seconds! Reusable & Leak-Free - This adapter is dishwasher safe & the leak-free design means no messes from accidental spills.