This convenient backpack expands to 24-40 liters with a side zipper closure. It's perfect for everyday use, school trips, sports, outdoor activities, and more. The backpack straps feature a chest belt. The body is water-repellent for easy water repellency. The main compartment features a PC pocket with excellent cushioning and urethane foam. The shoulder straps feature a mesh-like, memory foam cushioning for reduced fatigue even during extended use. The chest belt is height- and width-adjustable, allowing for a comfortable fit and active movement. The back is made entirely of mesh material for excellent breathability and reduced stuffiness. Pockets on the front and both sides allow for separate storage of small items.