With a wide quick release/fill 42mm cap and high-flow valve, the Speedfill SOFT FLASK 500ml/17oz 42 has an anatomical tilted design that fits comfortably close to your body makes staying hydrated faster and easier, so you can focus on the trail ahead. Shrinking as you drink to limit water bounce, the flask lets you know exactly how much you have left. Compatible with all Salomon caps featuring a 42mm opening.