sizeMedium: height 38CM thickness 15CM width 29CMLarge: height 42CM thickness 19CM width 32CMweightMedium: 0.53kgLarge: 0.58kgMaterial: NylonColor: blue, red, rose red, cyanThere are safety reflective strips, and there are reinforced stitching at the triangle of the bag, the handle, and the connection.LARGE CAPACITY & ORGANIZED: one main compartment roomy for daily necessities, such as clothes, notebooks, portable charger, etc. The front compartment has many small pockets, as well as pen pockets and a keychain design to keep your things organized and easier to find. DURABLE MATERIAL: Made of water resistant and durable polyester fabric, high-density nylon lining for better tear resistance, the heavy duty backpack with metal zippers ensures daily long lasting use. Serve you well as professional school backpackCOMFORTABLE: With a comfortable padded back design and thick and soft multi-panel ventilated pads, the big backpack gives you great back support. Breathable and adjustable shoulder straps relieve shoulder pressure to reduce discomfort in long packs. The backpack for boy gril will be a good partner for travel, school, work, business, etc Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.