I got this carrier for my cat who is 8lbs, and he fits perfectly. He took a few days to get used to it, but then he loved it! He loves riding in the car, and this is super for pet owners who travel a lot or just like taking their pets to the pet store. This carrier is so versatile and really changes what you expect from pet carriers. This is a car-seat, a backpack, a roller suitcase, and tote. Even on rides to the vet, I feel safer knowing he's secure should we get in an accident. The carrier fits great under airplane seats, and meets most airline regulations. I would recommend this to anyone who likes to have their pet with them. I don't think this size is good for much bigger than 10lbs animals though. It might be cramped for a 15lbs pet, but there are bigger ones by this company too. Really great purchase! I have no complaints.