26-45L expandable design: before extended is 26L, dimensions are 19.5 x 13 x 6.8 inches After extended is 45L, dimensions are 19.5 x 13 x 11.5 inches. You can expand the zip and buckles according to your requirements. The two handles set on top and one side, which allows an easy switch between backpack and suitcase. So it can be carried vertically or horizontally. The luggage belt on the back allows you to slide over the luggage tube, backpack very easy to carry, it is great for 3-7 days daily travel. Large capacity easy to carry: the backpack with many compartments, organisation and expansion. The main pocket can hold your travel goods, fits 5-8 clothes. It is cool that there is a wet pouch to liquids. Front compartment can also hold magazines, iPad and books and power bank which can charge your phone. 19 inch laptop compartment size: 16.5 inches x 11.8 inches (please cheak your laptop size), backpack back with padded batter can protect your laptop. Waterproof and anti-staple design: 1. Backpack back zip pocket protects your precious items, such as phone, passport, wallet from potential theft when travelling or lining up