Platypus is a classic brand for water bottles and hydration systems. This bottle can be packed completely flat when empty, and during use, its volume decreases as liquid is consumed: no air bubbles remain inside to cause sloshing. The SoftBottle is the manufacturers softest collapsible bottle. The material is durable enough to withstand rolling. It is free from BPA, BPS, and phthalates. - Leakproof cap - Threads are compatible with Platypus replacement caps - Tapered middle design provides a natural grip point