Large capacity backpack: 16.1 x 11.8 x 4.5 inches (41 x 30 x 11.5 centimeters). Errors (1-2 cm) may occur during the actual measurement process, and the actual size is based on the specific product size. Fabric: The backpack is made of high-quality polyester fabric, which is tear-resistant, scratch-resistant, comfortable, breathable, and easy to clean. The storage bag is made of cotton and linen fabric, which is durable and easy to store. Ergonomic design: According to the principles of ergonomic design, it consists of a shoulder strap made of a three-dimensional mesh and multiple layers of sponge to ensure optimal pressure relief and comfortable carrying. Applicable occasions: Suitable for all occasions, such as daily school, outdoor sports, shopping, fitness, gatherings, picnics, or travel. When you go out, you can put various items you want to carry in your backpack. Customer service: If you have any questions about this product, please contact us, and we will reply to you as soon as possible within 24 hours. Happy shopping!