Salomon Soft Flask Speed 500Ml - The Soft Flask 500ml/17oz Speed 42's thermoformed base, 42mm cap and high flow rate valve make drinking, filling and storing even faster and easier , so you can fully concentrate on the trail. The bottle becomes smaller as you drink so that the water doesn't slosh back and forth too much and you can always see exactly how much water you have left. Compatible with all Salomon closures with a 42 mm opening (purchase date from spring 2020).