Zojirushi Stainless Steel Travel Mug has vacuum insulation to keep beverages hot or cold for 6 hours. The leak-proof flip-open lid with safety lock prevents the lid from opening accidentally and covers the mouth area to maintain cleanliness. The nonstick interior is easy to clean. The stopper disassembles for easy cleaning. FeaturesZojirushi Stainless Steel Travel Mug has vacuum insulation to keep beverages hot or cold for 6 hours. The leak-proof flip-open lid with safety lock prevents the lid from opening accidentally and covers the mouth area to maintain cleanliness. The nonstick interior is easy to clean. The stopper disassembles for easy cleaning.