This hydration backpack perfectly combines a 3-liter leak-proof, BPA-free hydration bladder with a waterproof backpack made from high-strength nylon fabric with reinforced seams. Adjustable shoulder straps, a chest strap, and a breathable mesh lining ensure a comfortable fit even during long outdoor activities. The backpack's fabric is waterproof, moisture-resistant, and can withstand daily wear and tear. The adjustable carrying system allows the shoulder straps and chest strap to be adapted to different body types, while the breathable mesh lining distributes pressure. The lightweight design ensures comfort even during full-day activities. The built-in hydration bladder system allows you to drink hands-free, giving you greater freedom of movement. The hydration bladder's straw is positioned on the shoulder straps, allowing you to drink without taking off the backpack. This backpack is suitable for a variety of occasions, including hiking, camping, cycling, running, hunting, military training, and emergencies. The hydration bladder has a capacity of 3 liters, and the backpack's dimensions are 18 × 48 × 2 cm. Precautions: Before first use, rinse the inside of the hydration bladder with clean water and let it air dry before placing it in the backpack. Do not pour hot water, carbonated drinks, or sugary drinks into the hydration bladder, as this can damage the bag or promote bacterial growth. After use, empty the hydration bladder and let it dry completely; the backpack itself can be wiped clean with a damp cloth, but must not be machine washed. Store this product out of reach of children. Important: Sizes may be measured manually and may have an error of 1-3 cm; colors may vary slightly due to lighting conditions.