Zipper closure18" shoulder dropAt least 30lb bearing with high-strength aluminum alloy rod; Multifunction usage with armor bottom protection systemBig storage capacity with large multi-compartment design can hold more belongings, save your shoulders effortlesslyPersonalized design of shoulder straps padded pocket make your wheeling time more convenient and funCompletely new patterns could be suitable for different occasions, such as primary school, high school,college, nursing school, vacation,trip and so onWater can not soak through,The backpack fit for kids over 4 year-old. rolling backpack is a revolutionary wheeled bagdesigned specifically for school use, and is sturdy, ergonomic andpractical. It was designed by parents who got tired of seeing theirchildren carry too much weight in their backpacks, and of badly designedwheeled bags that break easily long before the school year is overChildren could begin using Roller as soon as they have too much weight to carry to school (more than 10% of their body weight), this usually happens around 7 years of age although it will greatly depend on the schoolWhy Choose an Rolling Backpakc?HealthROLLING BACKPACK helps kids to avoid possible injuries due to carrying too much weight in their backpacksPracticalityWith more than 38 liters (10 gallons) of total storage space,its easy to fit everything children need for school in a Roller. The multiple compartments will help kids to keep everything organized and well in sight.The laptop pocket accessory is ideal for children who need to carry portable computers to schoolLarge capacity Unique Patterns and Colors Durable CanvasQuality Construction