Front Expandable Space Capsule Bubble Window Pet BackpackFRONT Extension Cat Carrier Backpack for LARGE and Fat Cats up to 20 POUNDS. This cat bubble backpack carrier increases your pet's visual space via front transparent hard shell, Also the front extra 4" extension FIXS VENTILATION & HOT issues vs. non extension version. Are you still using the SMALL cat bubble backpack while your little kitten grows up. Your furry friend deserves to own a bigger one. That's the exact intention we launch this front