For days when we'll be logging big miles, we lace up our shoes, throw on the Salomon Active Skin 12L Reservoir Running Hydration Vest, and take to the trail. Rather than being a bag that you carry, the Active Skin features a streamlined design that functions like a second skin. The self-adjustable fabrics conform to our body, giving us a breathable, bounce-free fit that lets us bring all the gear we need when logging mile after mile. With room for an included 1.5-liter reservoir and plenty of pockets for cash, keys, and phone, this vest helps us stay fully hydrated so we can enjoy peak performance from the first step to the home stretch.