Thank you for calling me back and answering my questions. The Walkin' Wheels is the easiest dog wheelchair of all on market. One measurement is all you need. Fully adjustable, too. Dino loves his dog wheelchair. Every day we went for longer walks as he got used to the cart. We also got the optional harness for dachshunds and the drag bag. Again, thank you for giving him a second chance on seeing the outdoors and going places. - Douglas H.