I rarely write a review unless a product far exceeds my expectations, and this product deserves such a review.I stressed out about purchasing a wheelchair for our old lab at all because I didn't know if it would work, and then once I decided to risk it I stressed out about paying the high cost of this particular one. There are cheaper models out there. But then I saw a review where someone said they were glad they paid the "extra" dollars for this model because of the quality. I knew I was going to be paying a lot of money for even the cheaper models. Why throw that kind of money into a cheaper model I was more likely to be disappointed in? This model was a couple hundred dollars more than the one I was considering but the reviews were very different.I am SO GLAD I did. This is a sturdily built, very well engineered, highly adjustable, quality product.Our dog Java is not in pain, but has lost the ability to walk straight. His rear hips and legs give out on him.Java had no anxiety about the contraption I was building next to him, and was very patient with all the measuring and strap adjustments going on as we prepared the front harness. He was also patient and forgiving as we clumsily worked to get him in the rear wheeled part, and did all the necessary adjustments. Finally, we got him all strapped in, and he just started walking! Straight, supported, and like he had been doing it for years. His ears perked up, his eyes got bright and his tail began wagging. He loves his new wheelchair! He pooped and peed eight away with no issues, and got to actually enjoy a walk for the first time in months.My recommendation is that when you get this product, get some coffee, relax and take time to read through the entire manual prior to assembly, and go slow. Plan on a couple hours of assembly and adjustments, and an hour to work with your dog and dial in the adjustments. Take your time, relax, put it together right in front of your dog amd let him investigate, a lot. If he sees you in a good mood throughout the building process he is going to be far less anxious when you try to attach him to it.I will re-evaluate this product in a few months, but for today, I could not be more pleased.1 month edit....Our dog Java has gone from barely being able to go around the block to walking about a mile a day. He has gained a lot of strength and endurance. He still has difficulty walking unassisted, but that difficulty has lessened. More importantly is the incredible mental and emotional transformation. He gets so excited when I pick up his wheels now!I made 2 modifications. 1, I secured a couple layers of 3/4 inch padding where Java's back hip leaned into. This forced his posture to be more straight, and lessened the risk of his tipping the cart. This greatly improved his walks. 2. We live in a neighborhood where sidewalks are not great, and our walks take us across a lot of dark streets. Black lab moving slow is not a good plan, so I wired up his cart with an awesome rechargeable lighting system with white headlights, green running lights and red tail lights. This is an add-on idea the manufacturers should design and include as an upgrade option. Highly effective, and added to the cool factor of his wheels!I cannot recommend this product enough. This has added incredibly to not only Java's time with us, but his quality of life with us.