【Leak Proof & Spill Proof】 Engineered to prevent leaks and spills, good sealing performance allow you to carry, do sports, and drink with complete peace of mind, without worrying about liquid splashing. Upgrade your tumbler experience with SBMKK 40 oz Tumbler Flip Straw Lid. 1. SBMKK tumbler flip straw lid is specifically designed for 40 oz tumblers, compatible with Stanley, including Adventure, Travel, Quencher H2.0 FlowState tumblers. This tumbler flip straw lid is only compatible with Stanley tumbler. mugs. 2. The replacement flip lid ensures a perfect fit for your 40 oz Tumbler, and it is designed to be leak-proof, preventing any liquid leaks during use or storage. Made from high-quality plastic, these lids are food-grade, odor-free, and reusable for everyday use.