[Suitable Cup Size] The spill proof accessories are designed to fit YETI straw mugs in various sizes, including 16 oz, 20 oz, 24 oz, 25 oz, 26 oz, 35 oz and 42oz. [Dust-proof & Splash-proof] The straw topper prevents water from spilling and protects the straw from dirt and debris. making them perfect for outdoor activities like camping, hiking, or enjoying a day at the beach. Keep your drinks safe and clean. [High Quality Material] The material of the straw covers and spill stoppers are made of food-grade silicone, ensuring safety and durability. [Not Completely Spill Proof] Please note that there may be slight leakage due to the need for a vent-hole for air pressure balance. [What You get] This pack includes 3pcs Straw Cover, 3pcs Spill Stoppers (Note: Straws are not included). Any questions about the product, please feel free to contact us, we will provide a solution within 24 hours Neepanda