Made of Food grade environmental Silicone like baby nipples, safe,resistant, touches soft, roll it up easier, lightweight and non-toxic. Retractable and make it small to large water bottle. It use only one hand to make the bottle folded, and you can change the size into what you need. A tip, please make the cap open when you collapse or extend the bottle. Two mouths design, the Wide Mouth Neck that makes filling them easy, the small mouth in the top is easy for you to drink. The small twist cap adopts the clip design which can be opened and tightened. Sealed and Leakproof.