Checking firmware version

[Quisquose]

Sorry for asking such a stupid question, but how can I tell whether I have Merlin or Stock firmware installed?

I'm a noob, and a couple of years ago after buying my first wireless router (Asus RT-AC68U) I did a lot of experimentation and testing with various different versions (including Merlin). I can't remember what I ended up settling on, and checking the router just gives me a firmware version number, but no indication of whether it's stock or Merlin.

 

[RMerlin]

For a few years now I have a logo on the top banner. Version string should also be quite different, my firmware version always end with a version number somewhere between 1 and 67. Asus's last number will be much higher (oldest I have seen was 3.0.0.3.90).