"When I saw this product at the store, I thought it was great and that my dwarf hamster really needed it. When I got it home, I found it was pretty tough to put it together while my hamster, Lola, was in it becase I did't want to scare her. Also, I wouldn't recommend this for dwarf hamsters because they seem to be too small to operate them. Lola loves to run in her ball since she can go anywhere she wants, but this carriage only goes forward and backward. Although it's an adorable idea for spoiled hamsters, I think a simple critter ball works better."