Event Gear thermal bottles keep your fluids either a little colder, or if you ride in the winter, a little warmer ! The Event Gear bottles feature an insulated double wall construction, and are made from BPA-free plastic. This bottle also features a new inuslating sleeve that doesn't have the crinkley feel of other thermal styles. This bottle is standard sized, meaning it should work with most common bike bottle holders. Capicity is 500 ml of fluid- aobut 20 oz. A standard pull valve makes it easy to use. A very nice bottle that you will love to use on the bike, as well as everywhere you go-to work, gym, etc.!