Product description Size: The backpack measures 29cm in length and 41cm in height Water bag: 351*175mm Color: gray, black gray, gray red Material: Nylon Package content: 1pcs outdoor sports backpack 1pcs outdoor sports water bag 1.COMFORT FOR YOU: Ergonomic design with adjustable belt and chest strap suitable for men, women, and children. The chest straps ensure stability during movement. Ideal for hiking, running, marathons, cycling, and travel. This drinking backpack with a hydration bladder is also a great companion for biking. 2.[High Quality Material]: Lightweight and waterproof high-density nylon, rope construction, premium buckle, providing a comfortable fit without adding extra weight during activity. EVA foam padded back and shoulder straps with ventilation channel and quick-drying materials for superior breathability and comfort. 3.Running backpack with hydration system: bladder compartment with hanging system, compatible with a 2L hydration bladder that meets FDA standards. The extra-large screw cap allows for easy filling of the hydration bladder. The removable hose simplifies cleaning��just rinse, empty, and flip. 4.Perfect outdoor equipment: lightweight jogging backpack featuring a unique design for optimal comfort and freedom of movement. Reflective elements enhance visibility in low-light conditions. This running backpack includes a heat-insulated compartment to keep your drink hot or cold for hours. 5.[Lightweight, splash resistant, and durable]: Ideal outdoor sports gear crafted from lightweight and water-resistant nylon, with padded shoulder straps for comfort during long-distance running, hiking, and cycling.