Food-grade silicone: Made from premium quality silicone rubber, these protective silicone are not only safe , but also reusable. Spill stopper is made from premium food-grade silicone, providing you with a premium and safe drinking experience. you can enjoy peace of mind knowing that your health is always a top priority Fit: The Silicone Spill Proof Stopper designed to fit for 40 oz stanley cup 30 oz tumbler with handle. These Silicone Spill Proof Stopper are precisely engineered to match the exact dimensions of your favorite tumbler, ensuring a snug and secure fit Spill-proof: Installed in the straw hole of the lid, it not only forms a seal, but also holder the straw and can stop debris and dust from entering through the straw. The silicone Spill Proof Stopper designed to fit for stanley cup accessories significantly reduce spills, providing an improved leak-resistant solution for stanley Straw-friendly: The Silicone Spill Proof Stopper including 4 Straw Cover Cap, 4 Square Spill Stopper and 4 Round Leak Stopper. The Straw Cover Cap is compatible with straws less than 0.39" / 10mm diameter. It is compatible with most straws to ensure more convenient drinking Easy to install: Our designed for stanley 40/30 oz tumbler spill stopper is incredibly easy to install. These accessories can be easily inserted and press it down firmly. It used without any hassle or difficulty. Whether you're traveling or using it in daily life, the stanleytumbler accessories will keep your drinks inside the cup and surroundings mess-free Patent Pending:Our Stanley cups have three options, there are Silicone Spill Proof Stopper 1.0 and Silicone Spill Proof Stopper 2.0, when you have version 1.0 Stanley cups and version 2.0 Stanley cups, you can choose the Size. Version 1.0&2.0-6PCS Silicone Spill Proof Stopper for Stanley