Just wanted to give people an example of how tiny and terrible Critter Trail cages are for hamsters. This is an old Critter Trail cage sitting inside of a DIY cage im currently building for my future Syrian hamster. The Critter Trail is dwarfed by comparison. Hamsters need an absolute bare minimum of 450 square inches of uninterrupted floor space. This means multiple cages or tall cages with lots of levels and a small base don't count and are bad for your hamster. Please don't ever buy one of these for your hamsters or mice. They're tiny prisons and not fair to your pet.