Kindly please be advised that: This is a kind of lightweight foldable backpack. To meet the folding and ultralight purpose, the backpack made of soft & flexible nylon material. It is NOT a hard stiff shell backpack. There is NO padding or protection on the back and underside. We DONT suggest to use this as a school bag. Due to the shoot light & brightness tolerance between display monitors, colors will be slight different. Specifications: Colors Optional: Black/Green/Bright Green/Blue/Purple/Rose Red/Orange/Sequin Blue/Sequin Purple Foldable: Yes Capacity: 20 liter Material: Water resistant ( NOT waterproof) soft nylon Weight: normal packable backpack: 0.23kg ; foldable sequin backpack: 0.26kg Unfold: 42*32*17.