【adjustable straw】easier to drink, you can pull the stem to extend it and retract it once you've finished drinking to prevent it from getting in the way. 【anti-sloshing】easily carry your water during your trails, runs, or hikes. The soft TPU flask expels air when you drink to prevent sloshing and water noise. 【leak-proof】thanks to its bite safety valve, the water does not spill. 【recycled plastic】made from recycled TPU. A 500ml flask made from recycled materials, with a bite safety valve, ultra-practical, comfortable, and easy to clean, compatible with most hydration packs.