Convertible & Hidden-type Design - Skillfully designed to be a laptop messenger bag / shoulder bag with single shoulder straps, or used as a backpack with backpack straps which is hidden-type. Main compartment zippers is designed to be hidden type, that looks nicer and anti-theft. Well Organized & Protective - Built-in laptop and tablet PC sleeves of thick soft foam padding and velcro fixed strap provide extra protection for your devices like laptop, ipad from bumps, impacts, and scratches. Various pockets is reasonably designed to organize your essentials with ease. Water-resistant & Anti-tear - Made of high quality water-resistant nylon materials & anti-tear lining with excellent sewing, that keeps your inside items still dry from splashing, even on rainy day on go, and not easy to fray. Sizes- Exterior: 48x34x13CM/ 18.9 x 13.4 x 5.1I nch, Laptop compartment: 45x30CM/ 17.7 x 11.8I nch Fits most up to 17.3 inch Laptops, but may not snugly fit some models. Weight: 0.95KG / 2.1 lb