Description: 【Lightweight and Stable】: This professional road running vest hydration pack is designed for competitive , offering lightweight and stable support that doesn't during movement. It features a quick and easy loading system for your convenience. 【Ample Storage Capacity】: The hydration pack can hold a 5-8L water bladder at the back, two 500ML soft water bottles at the front, along with small items. It's great for marathons, outdoor sports, mountain climbing, hiking, and cycling. 【Thoughtful Design】: The front of the hydration vest includes hidden outlets on both sides, a storage compartment for a survival whistle, two multifunctional pockets on each side with secure bottle holders and adjustable chest buckles. The back features reflective logos and bands for night visibility, large storage compartments including 1 specifically designed to hold a water bladder or other heavy items securely in place. 【Suitable Size & Material】: This universal size is suitable for individuals weighing between 50kg-80kg. Made from nylon material with product dimensions of 42cmx47cm/16.54inchx18.50inch. 【Package Includes】: Each package comes with 1 professional road running vest in black color under 20L capacity. Specification: Material: Nylon Size Chart: 42cmx47cm/16.54inchx18.50inch Package Includes: 1 Hydration Vest Note: Please allow slightly errors due to manual measurement and different monitors.