Compatibility - Fits most 20oz tumbler brands with an inner mouth diameter of 3.15 inches (80 mm), including YETI Rambler, Ozark Trail tumbler, Old Style RTIC tumbler, and other cups with similar specs. Splash and Insulation - Black silicone O-ring seals the cap edge to help prevent leaks. - Thick cap design contributes to better insulation, keeping beverages cooler or hotter for longer. High Quality Material - Made from high quality plastic, BPA-free, eco-friendly, shatter-resistant, sturdy and durable, and easy to clean. - Dishwasher safe; avoid using in microwave. Magnetic Spline and Crystal-Clear Caps - Magnetic slider cap is easily attachable and removable, and simple to clean. - Note: the magnetic cap slider helps prevent spills but is not designed to be leakproof. - Drinking hole allows direct sipping or use of a straw, while keeping the drink from touching your nose. Crystal Clarity - Crystal-clear caps allow you to see if you need to refill at a glance. Use Scenarios - Daily commute or office use: keep your favorite beverage at the right temperature throughout the day with an easy-to-clean, compatible lid. - Outdoor activities: great for hiking, camping, or picnics where spill prevention and visibility of your drink level matter. - Travel or errands: convenient for road trips or quick trips to ensure a reliable lid option that supports direct sipping or straw use.