Description: 【Breathable Performance】:The hydration vest backpack features a breathable mesh back panel and shoulder straps, ensuring you stay cool and comfortable by wicking away sweat during intense activities like running, hiking, or climbing 【Storage for All Your Essentials】: This hydration vest pack boasts a powerful storage system to easily meet your outdoor needs 【Enhanced Visibility for Nighttime Safety】: This outdoor sports backpack vest is equipped with strategically placed reflective strips on both the front and the shoulder straps 【Built for the Outdoors】: Crafted from high density, tear resistant Polyester, this running cycling chest pack reinforced with tight webbing, smooth gliding zippers, and heavy duty, high plasticity buckles, guaranteeing reliable performance and durability through countless rugged adventures 【Versatile Design】: Perfect for a wide range of sports, this hydration pack for hiking climbing features adjustable straps and an elastic bungee cord system to create a snug Specification: Material:Polyester   Size Chart: 21cmx2cmx36cm/8.27inchx0.79inchx14.17inch Package Includes: 1 Hydration Pack  Note: Please allow slightly errors 1-2cm differences due to manual measurement.