Good fitting begins with the accuracy of measurements you provide. (Please refer to our measuring instructions.) Adjustability in width, height, and length are provided since we understand how difficult it is to measure your disabled pet exactly. A properly adjusted cart is essential to provide balance while in your K9 Cart. When properly fitted, our carts should never lead to pressure sores. We offer custom measuring and fitting at our shop in Oxford, MD at no extra charge. Should you not be able to come to our shop, we highly recommend sending digital photos (including top, side and front) of your pet in the new dog wheelchair to evaluate your fit. Please call with questions to help us with any fitting problems.