Engineered to deliver fast and efficient hydration during intense endurance training, the USWE 0.5L Rocket soft flask provides a lightweight, flexible solution for competitive athletes. The specialized wide-mouth opening is built for quick refills at race aid stations, allowing standard ice cubes or hydration mix powders to drop inside effortlessly. Designed to compress completely as you drink to minimize liquid slosh and maximize stability, it is compatible with USWE Vest VST models, but the 500ml size and collapsible design means it will fit most hydration vest front pockets.