1. and breathable: This running vest made of lightweight, breathable material and mesh fabric has breathable openings that improve air circulation and moisture wicking. Provides good air circulation in the chest area to avoid heat buildup and discomfort. 2. Adjustable design: The ultralight hydration vest is ergonomically designed and has an adjustable waist and chest strap that effectively distributes weight and reduces energy consumption. The adjustable straps on the chest and sides provide excellent stability, reduce bouncing and slipping and provide a good fit for runs. 3. Reflective strips: The backpack has a reflective strip design at night that serves as a warning when training with a light source at night to ensure . Features subtle reflective label and strap details for added visibility during lowlight training runs. 4. Plenty of storage space: This running vest has two storage compartments on the shoulders and a large mesh pocket on the back, ideal for storing energy bars, snacks, keys, cash, towel and other important items needed when running. It is also equipped with a drawstring so that nothing can fall out.