The Trainer is an affordable, easy to use, entry-level backpack dog carrier. Available in sizes XS-L, it is ideal for smaller breeds, dogs that are still growing, training, and learning to socialize. Available in a variety of bright color options, the trainer should be used for short, non-strenuous activities like short walks, hikes, public transportation, and other similar activities. This carrier fits most comfortably on dog owners with a small to medium build. Safety: All K9 Sport Sack carriers are specially developed under the close direction of animal professionals, veterinarians, dog trainers, and outdoor product engineers to be ergonomic, safe, and strong.