Thoroughly inspected by Toby.
The Dakine WNDR Pack 25L is a practical daypack which you can also use when you exercise or want go hiking. With a capacity of 25L, you have enough space to take some extra shirts, books, or other accessories with you. And you can put a drinking bottle in the mesh side compartment. The bag also has a 15-inch laptop compartment, so you can also use it to go to work or class. Haven't fully packed the backpack? You can tighten the elastic belt on the exterior, so the backpack remains compact. You can also attach your bike helmet or jacket to this, for example.
Note: the size of your laptop, such as 15 inches or 17 inches, is the size of the screen, not of your entire laptop. If the bezels around your screen are wide, choose a laptop compartment that is a size bigger. This way, you can be sure that your laptop fits.