insulated cups are very durable and can be taken to hikes, morning commutes, work, school, and camping trips. Double wall vacuum insulation provides maximum heat and cold retention. Whether you use this tumbler for cold lemonade during the summer or hot coffee during the winter, it holds the given temperature for hours. Take it anywhere and don't fret over spills! The side-lock lid prevents spills and leaks. The friendly, ergonomic design can fit most cup holders.