My daughter uses this well-made and durable carrier to transport her Maine Coon cat (about 15 lb) when she is traveling. The backpack feature is excellent (good straps and balance), leaving her hands free for other gear. This pack is at about the limit for this size of animal, but the cat likes tight spots and is quite comfortable when the pack is in the upright position, looking out the mesh windows at the passing scene. My wife made a simple cover for the pack to keep the wind and rain out. Having this carrier allows my daughter to travel easily as a foot passenger on our local buses and ferry when she visits us.  One thing I added (and may have been lost at customs) was two screws to secure the base to the pack.