Our dog is a little Cairn Terrier cross, and her little legs are having problems with arthritis, which has gotten worse as she reaches her old age. Instead of leaving her at home when we go on long walks or hikes, this backpack allows us to bring her along, as she loves walking, and just wants to be with her humans. We completed the guide online to find the right fit for her and the pack works wonderfully. It was difficult to get her in the first time, but she now knows she gets a free ride in this thing and no longer struggles, she loves it. The zipper is easy to close without catching the dog's fur, and the pack has lots of ventilation with safety straps and an extra pocket on the outside to hold her water bottle. The straps are comfy for the human carrier.My only concern is that it would be great if it had a waist strap to help distribute the weight and a chest strap to help keep the shoulder straps in place, similar to a hiking backpack. The dog gets quite heavy after a while and I tend to walk with my hands under her bum to take some of the weight off my shoulders.Très bien dans l’ensembleMuy cómoda para los perros y para nosotros los dueños. Llego muchísimo antes de lo planeado.All in all this is a good bag. Might take a little coaching for your dog to sit down property in the bag.