This multifunctional backpack by Athacer is made out of water repellent polyester with polyester lining material. The bag cannot be opened from the front, it is opened from the back to prevent theft. The internal space of the bag is completely structured with several pockets and holders for your phone, wallet, tablet or any other items. On top of that, there is a handy spot in the straps where you can keep money or cards for easy access. On the right bottom side of the bag there is a handy USB 3.0 port. The port can be used in combination with a power bank (not included) that can be connected on the inside of the bag. The strap is extremely comfortable with decompressing pillows to divide pressure over your shoulder. The back of this bag is completely ventilated with breathable material, this way you won't get sweaty under the bag. Model numberBP053TypeBackpackColorGrayShapeBoxMain materialWater Repellent NylonLining materialPolyesterPatternSolidStyleFashionDimensions43 * 11 * 26 cmCapacity20 liters