Klean Kanteen's most popular size, the 27oz Kanteen Classic is perfect for your on the go life. Whether youre trying to juggle a full day of classes or work, or a trip to the dog park between your workout and happy hour, just one or two fill ups will help you stay hydrated and happy all day. The 27oz is available with the Sport Cap 3.0 featuring a soft silicone spout, 25% higher flow rate and 'chirp' free hydration. Easy drinking and no whistling sound! Klean Kanteens are made from high quality, 188, food grade stainless steel totally free of BPA and other toxins. Because stainless steel itself is safe, we dont need to coat the inside of the bottle with a plastic or epoxy lining, one of the main differences from aluminum bottles.