so what do you guys thing about it ? should i buy it and will it work for airmon-ng?
When I was looking for a small RT5370 adapter for nethunter I got a MT7601u/RT8188. It's not working with Nethunter but it works surprisingly fine with Kali (2017...). You can use airmon-ng and airodump-ng and as far as I remember injection is supported, too.
Buy it, try it, keep it, or throw it away. It costs nothing!