Built to fit your active lifestyle, Thinksport™ water bottles are made of stainless steel and provide an alternative to bottles containing Bisphenol-A (BPA). High quality design with double-walled construction, vacuum sealed. This design is found in high quality products such as Thermos containers so these bottles do not sweat, and keep contents hot or cold for hours. We at Berkey Filters searched the world over to find the best water bottle available and the Thinksport is it. Known as the Cadillac of water bottles. Available in 750 ml (25 oz.), 500 ml (17 oz.), and in the 350 ml (12 oz) model. NOTE : The Thinksport Water Bottle does not have any filtering qualities.