My little 9 lb dog gets tired on long walks, and this carrier makes it so easy to push him along for a rest so I don't have to carry him. The wheels rotate in all directions, so it goes over small bumps and rolled curbs easily. The aluminum frame is light but sturdy, and is collapsable, and both the frame and the wheels are easy to remove when flying and we have crate height restrictions when on board. The only small problem is that the back of the carrier does not easily push forward a little (like my dog's old carrier) for getting it under an airplane seat for take-off and landing. I can \"force\" it sideways without any damage -- hopefully enough to fit it under the seat in front of me when we fly next month. It would be a perfect carrier if the back of the crate could be slightly pushed inward for sliding the back under airplane seats for take-off and landing. Overall a great carrier, and I would purchase it again.