I think that the middle part can removed, but not sure. In my country the cage with the spacing bars less than 12mm is a smal cage. The large cage are for ferret - that one at the picture with 15mm space bars and cage for parrot, but for the parrot the space bars is large then 12mm and 15mm.
In the moment this is the best large cage that I can find, but I really worried that my glider will go out :( I want large cage for her and want she can bounce and climb and play in more space.
1/2 inc is 13mm I really hope that 15mm is not a problem