Hello. I am pretty sure the 28cm wood trixie wheel fits - people have had them in maxi duna multys which are the same height. I can't measure mine as I took the base off and it's screwed upside down in the cage.
One that will fit but is an expensive option, is this rodipet one. It's also height adjustable - minimum height 30.5cm - max height 42.5 cm. I had the smaller version for a robo and plastikoted the wheel and cork surface and it lasted really well.
It's 28cm diameter externally and 27cm diameter internally
ø 27 cm Rodipet® Super Silent Cork Exercise Wheel