Deuter Streamer Flask 500 ml - transparent Ultra-light soft flask with leakproof Helix bite valve. Features of the Folding Bottle:- soft, foldable, odor- and taste neutral material shrinks as you drink to limit water bounce large screw cap opening for quick access and easy cleaning stows easily in side pockets or vest-style shoulder strap pockets (like the Ascender) dishwasher safe Materials: PVC and BPA free