Airflow Relief Valve: Large opening enhances straw drinking experience. Contoured Straw: Made with mouths in mind, a wider opening means easier sipping with minimal effort. Twist-In Locking Straw: Zero tilting required. Cupholder Friendly: Both 30oz and 24oz fit most cupholders. Folding Loop Handle: Comfort grip coating. Grab and go with just a finger. Clean-Lock Covered Lid: Click the button up/down to lock or unlock. Silent Silicone Base: Silicone base for soft landings. Pat/Pat Pending