Straight from the innovation team of dbest products comes the smart backpack. With the smart backpack you get a 4 -in-1 Combo. You get a backpack, great for use to carry school supplies. Place it on the ground and it becomes a rolling backpack great when you are traveling or simply just on the go. Put the backpack on its side and it becomes a duffle bag, the quintessential bag for the inner athlete in all of us, use it to go to the gym or use it to carry your soccer equipment on and off the pitch. You can also remove the backpack and it converts into a functional lightweight durable aluminum Dolly capable of carrying 50 lbs. It has a cover for the wheels to prevent your clothes from getting dirty, made of that same high quality nylon on the backpack. Ball bearings on the wheel create an EZ glide wheel system. Backpack is waterproof and cleaning is simple just do not wash with hot water.