When 27 ounces just isn't enough, this is. The 40oz Kanteen Classic is great for long car trips, camping, a late-night session at the office, a trip to the beach or any time you need to carry a lot of liquid and don't have the option of easy refills. Just like every Klean Kanteen, it's made from high quality, 18/8, food-grade stainless steel that's totally free of BPA and other toxins. Because stainless steel itself is safe, the inside of the bottle isn't coated with a plastic or epoxy lining, which is one of the main differences from aluminum bottles. Food-grade stainless steel is used in the brewing, food and winemaking industries too. It's the material of choice because it doesn't retain or impart flavors. No matter how many times you refill it, no matter what you put into it, your Klean Kanteen will keep your drinks fresh and clean tasting. The Loop Cap was designed with athletes and multitaskers in mind. The handy attachment loop makes it easy to clip your Klean Kanteen onto your backpack, climbing harness, messenger bag or any other place you need quick, easy access to your drink. Made from polypropylene (pp#5), which contains no BPA or toxins.