Stem raiser with a notch at front

[pistonheadforum]

Hello,

I've put the following stem raiser on my mountain bike and it's made a massive difference to comfort:

https://www.tredz.co.uk/.System-EX-Alloy-Stem-Rais...

I'd like to do the same on my touring (dropped handlebar) bike but notice that the stem on that has a notch (key?) on the front that means the stem is not completely round.

I'm guessing that just getting the same one above and fitting will be a problem even if it's the right size?

Is there something I'm missing or a different type that's needed for a keyed stem?

Many thanks in advance.