Compatible with Strive Fly, Strive 5 and Strive 10 running vests, the Silva Soft Flask 500ml lets you stay hydrated without slowing you down. Made from a soft and flexible material that weighs only 44g, the Silva Soft Flask 500ml features a self-sealing nozzle for easy drinking at pace. An easy to grip 40mm cap makes it easy to open, fill and wash. This 500 ml soft flask is soft and flexible and transparent, allowing you to see how much liquid remains. The self-sealing nozzle makes it easy to drink on-the-go, and the easy-to-grip 40 mm cap allows for simple opening, filling, and washing. It is made from soft and flexible TPU material, free from BPA, phthalates, and PVC, and weighs 44 g. The flask is designed to fit the front pockets of running vests and features adjustable straps to ensure it stays securely in place. It is available in a light gray and transparent color.