The main compartment of the Backpack (dimensions about 42 x 27 x 15 cm) is closed with a two-way zipper. The inside is without any additional compartments so even special and large items can fit in. Packing smartly is wise; for instance, folding one’s change of clothes and putting them against the back. This way, the Backpack would function as a back cushion.
At the side, open flat pocket compartments (dimensions about 22 x 15 cm), where water bottles or even an umbrella fit easily.
The outer pocket (dimensions about 15 x 23 x 5 cm) is closed with a zipper. It is convenient for smaller items, which might be needed quickly.