COMPATIBILITY - Fits 2.28 inch wide mouth bottles, compatible with Hydro Flask (12-64 oz wide mouth models), Simple Modern, Iron Flask, and other similar brands. Important Note: Not suitable for TAL, YETI, Nalgene, or standard/narrow mouth bottles—mismatch will cause leakage. ATTENTION PLEASE - During the initial use with hot water, the steam generated by the hot water will form mist upon contacting the soft silicone at the spout. The release of this steam might appear as water leakage. This is a normal phenomenon. Simply release the pressurized water during the first use, and there will be no further water leakage in subsequent uses. UPGRADED FLEXIBLE HANDLE & SPOUT - The push-button design allows for effortless one-handed drinking. Designed for comfort, the upgraded handle reduces finger pressure, making it easy to lift and carry with just three fingers. Smooth Spout: The glossy, smooth spout offers a comfortable drinking experience, while the specially designed silicone seal ensures leak-proof performance and easy cleaning. SAFE & DURABLE MATERIAL - Made from upgraded BPA-free PP material, this lid is safe for kids and adults alike. The drop-resistant design ensures durability, even if accidentally dropped during play or outdoor activities. EXCELLENT CUSTOMER SERVICE - If you have any questions or concerns, feel free to contact us. We respond within 10 minutes during business hours to ensure your satisfaction. The Push Button Lid is designed for an easy, one-handed drinking experience. The chug-lid design opens with the push of a button for high liquid flow and one-handed drinking.