1. Perfect Replacement - This magnetic cup lid is designed to fit YETI 30oz Tumbler, 14oz Mug, 26oz Cup, 30oz Tumbler and 35oz Sippy Cup. (Please note: This lid is not compatible with Rambler Bottle or Travel Mug with Strong Lid.) 2. Spill-proof and Insulated - The black silicone O-ring wraps tightly around the cup to prevent leaks. The thick lid keeps drinks more insulated, cooler or warmer for most of the day. It prevents spills, but it is not meant to be stored in a bag, and if you leave it in the car, it seals well to prevent splashes. 3. Stylish and Practical Design - The tumbler replacement lid features a sturdy double seal design and two strong magnets for smooth and secure opening and closing. No bumping your nose when drinking. The slider is removable for easy cleaning. 4. Safe to Use - Made of high-quality, shatter-resistant and BPA-free materials. Even after repeated use for many years, it remains crystal clear.