This is the best cage I have ever had and I will never have my rats in anything other than the Critter Nation! It is spacious, easy to clean, convenient to be able to lock the ratties in the lower half while cleaning the upper half. The design is great, it was easy to assemble. I HIGHLY recommend this cage! It is completely worth the price and if I get more rats, I will buy another! The smallest of baby rats cant get out the bars which is great! it is heavy duty, and made with quality material!