If you are going to spend the whole day on business, then the Minimal leather backpack from Plab company is the perfect thing that contains your life.
The main compartment closes with a metal zipper. Also, a secret zippered pocket is on the back for a passport or money.
Inside is a divider for A4 format documents or a laptop; two pockets accommodate an A6 notebook, passport, wallet, etc.; one pocket for a phone or key ring on the other side, which fastens with a metal button.
Leather straps are reinforced with belt tape and adjustable with buckles.
A handle-holder is placed in the upper part of the backpack.