Mighty Mug is powered by our innovative and patented Smartgrip Technology. Simply place Mighty Mug down on your desk and it creates a powerful airlock which allows Mighty Mug to resist accidental knocks to help avoid spills. When you lift Mighty Mug the pressure is instantly normalized allowing the airlock to release and Mighty Mug to lift naturally. You need to try it to believe it.• Smartgrip technology grips when you accidentally knock it.• BPA free.• Car cup friendly.• Dish washer safe.