Klean Kanteen is the original, eco-friendly, BPA-free, steel water bottle. We love them because you can put them right in the fire (without the lid, or course) for boiling water or cooking food. The 40oz wide is the ultimate bottle for the backcountry. The extra wide opening is more than 2 inches in diameter for quick filling, pouring and cleaning. Even though it holds 8 ounces more than a quart-sized bottle it easily fits into our stainless steel cup. Made from high quality, 18/8, food-grade stainless steel that's totally free of BPA and other toxins. The inner lid is also made of 18/8 stainless steel.