Specification: Large storage space, large capacity main pocket for A4 magazines, everyday clothes and other items.Breathable back, comfortable to carry, back made of breathable sponge, soft, comfortable and breathable. Material: Polyester/canvas Opening method: zipper Applicable gender: neutral Function: breathable, waterproof and wear-resistant Weight Dimensions: Three-piece set: 0.55kg; 17 inch backpack: 0.30kg; 44*28*13cm Satchel: 0.18kg; 25*19*8cm Pen case: 0.07kg; 22*11*5cm The package contains: 1* Pen bag or 1* Satchel or 1*Backpack or 3pcs (pen bag+satchel+backpack) Note:1. Due to manual measurement, there may be a slight tolerance of 1-3cm. 2. Due to differences between different monitors, the picture may not reflect the actual color of the item. 3. If you need to buy a three-piece set (pen bag + satchel + backpack), you must choose the SKU of 3Pcs. If you buy a pencil case, the package you receive will only be a pencil case, not a three-piece set.