This is a Patagonia MLC mini. I bought this bag as a personal item for a trip in Japan, but I discovered how incredibly practical it is for short or urban trips. In the photo I’m coming back from a weekend at the beach. With this bag I could easily pack 2 liters of water, 3 towels, a straw mat, some clothes and accessories. I also had a beach umbrella that comes with a sack featuring a simple strap to hang it on the shoulder, but I was able to fix the umbrella to my backpack, using both my self-made X net on the front and snapping the strap to one of the many available points using a snap-hook. So in a nutshell it is capable to store a lot of stuff in the inside (~24/30 liters) and also a lot of stuff on the outside with the only limit being your imagination
Yeah he’s him