Looking online for backpack with numlock popular in 🇩🇪

I know this sounds as a strange req, but let me tell you why.

I went in Germany (Hamburg) a couple of months ago and I noticed lots of people using backpacks waterproof (like this ) having also a numlock, and I started being really interested in buying a similar one. However, in my country (Italy) it seems this bag type is not so common, so I'm trying coming back to "the origins" and asking you: could you please suggest me one or more brands that sell it? It would be really appreciated!!! TY