@Rikk - below is a picture of my wae2 with a kayfun lite
Here is a picture of the wae2 with a squape Reloaded (somebody told me you like this tank)
I can't find my aqua (21mm) or my erlkonigin (21mm) to show you the difference, maybe somebody who's more organized than I am can post similar pictures for you to see.
Ignore the gap, my wae2 510 pin is messed up and my replacement is stuck in customs (since April 4th)

Here is a picture of the wae2 with a squape Reloaded (somebody told me you like this tank)

I can't find my aqua (21mm) or my erlkonigin (21mm) to show you the difference, maybe somebody who's more organized than I am can post similar pictures for you to see.
Ignore the gap, my wae2 510 pin is messed up and my replacement is stuck in customs (since April 4th)