You always want big cages for hamsters usually you want 360sq. Inches or bigger because if they are in smaller cages it will get the hamsters stressed out. If hamsters get stressed out they will not let you hold them and it will shorten their life spand. You want a cage like the one on the bottom not the one on the top. Although the one at the top looks playful you can't fit a basic hideout, other toys and their chews.