Vapur Anti-Bottles are completely BPA-free and are constructed of three layers of ultra-durable plastic. The innermost layer is made from FDA-approved polyethythene, which is then bonded to two layers of nylon for strength and durability. Every Anti-Bottle is designed to withstand everyday use and regular cleaning. The inner layer is odor, taste and stain resistant, so it can safely be reused again and again!The Anti-Bottle is designed to stand when full and can be rolled, folded or flattened when empty, making it easy to use and carry everywhere you go. Unlike rigid water bottles, that are bulky when empty, the Anti-Bottle can be easily tucked away, conveniently fitting into pockets, purses and packs.