Housing upgrade

[Zeroshero]

I am going to start looking at x-pens for Zero's next living accommodations I have two 42" high pens already but I think that is a bit much and I think the bars are still too wide. How high is ideal for a bunny pen?

 

[Watermelons]

42" high sounds just fine. Some rabbits can jump super high, some don't, but you never know they can or will until they do.
How wide is the bar spacing and how big and old is the rabbit?