You can fit a 12" plastic Trixie in if you just have no bedding underneath. The wooden trixie is a bit trickier, I had to turn my lid upside down but it still fits.
I'd recommend it if you have no way of making a different DIY cage. It's weirdly shaped and not really deep enough for you to get a lot of bedding in for burrows. Usually they can reach the mesh of the lid so there's still an opportunity for chewing on it. It's a very easy way to get a lot of space and I do still use mine but yeah, there are better options out there if you have the access to tools etc
Now that I've made the
Linnmon DIY cage that's what I'm pointing everyone to.