Back Expandable Bubble Cat Backpack Carrier：This cat bookbag features a back expandable design. When expanded, it doubles the interior space, making it suitable for cats of various sizes, fit up to 13 lbs. It’t also suitable for bunnies and puppies. High-quality materials: The updated and improved double-headed zipper glides smoothly. The bottom of cat travel carrier backpack is reinforced to ensure the stability of the bag when kittens enter or exit. The pet-friendly material is scratch-resistant, non-deformable, waterproof, and easy to clean. Multi-Directional Ventilation System: 9 airflow vents + breathable mesh panels ensure air circulation to keep the kitten comfortable. The side pocket allows for convenient storage of pet supplies. The other side pocket allows the kitten to stay in contact with you, it suitable for kittens that are easily nervous. Large Back Expandable Design: Measuring 15"L x 11"Wx 18.5"H, expandable part size is 17.3''L x 18.5''H. It fits medium cats and dogs up to 13lbs. The large internal space allows your furry friend to move around freely and comfortably. The built-in safety hook lock can effectively prevent kittens from jumping out, providing reliable safety protection. Panoramic Bubble Window: The crystal-clear transparent viewing window allows curious cats/dogs to safely observe their surroundings. Ideal for stress-free vet trips or airplane travel. Ergonomic Load-Reduction Tech: The widened shoulder straps and chest buckle can relieve pressure and stabilize the position of the cat carrier. The adjustable shoulder straps are suitable for pet owners of different heights. Back Expandable Bubble Cat Backpack Carrier: This one - of - a - kind cat carrier has a back expandable feature that doubles the interior space. It's an excellent travel cat backpack for activities like hiking, traveling and camping. Breathable Back Expandable Bubble Cat Backpack: The multiple round holes and mesh panels on this back expandable bubble cat backpack guarantee great airflow. Its lightweight build makes it a top choice for transporting your cat on trips. Stylish & Practical Travel Cat Backpack: Offered in various colors including black, pink, and purple. This back expandable bubble backpack cat carrier not only has an attractive look but also practical elements like adjustable straps and a security lock. Lightweight & Spacious: Measuring 29 x 15 x 19 inches and weighing just 2.8 pounds, this travel cat backpack provides enough room for your cat and is easy to carry. The foldable design adds extra convenience. Comfort - Focused Design: The soft cushion inside the back expandable bubble cat backpack, combined with the expandable function, keeps your cat cozy during long travels. It's the ideal back expandable bubble backpack cat carrier for any adventure.