【Multifunctional organization bag】 The backpack has several storage spaces. You can store small items (like keys, coins, cell phones, cards, towels, etc.) in multiple storage bags that are convenient to carry and do not take up space. , 【Large capacity】 Main compartment + front compartment = 20L / 30L. The backpack is made of ultra-light, waterproof and tear-resistant nylon fabric, which is more durable and long-lasting. The side mesh pocket has a capacity of 1.1 liters. The backpack contains: rain cover, bicycle helmet mesh compartment, key pocket and so on. , 【Ventilation and comfort】 The mesh fabric on the back can improve airflow, achieve maximum ventilation while supporting the back. Adjustable hip and chest straps secure the bike backpack and improve comfort and stability. , 【Upgraded design】 Compatible with the hydration system, with a concealed H2O outlet on the shoulder strap for refilling water (without a hydration bag). You can drink water anytime while riding a bike. There is also a lifeguard whistle on the backpack adjustment belt, which is ideal for outdoor activities. , 【Reliable safety guarantee】 The reflective strips on the backpack ensure safety when driving at night and are suitable for cycling, camping, mountaineering, hiking, etc.