The critter universe expansion kit allows layer upon layer of new living space to be added to the critter universe cage 02200 and 02211. Included are cage, floor, tunnel, water bottle, bowl and two connector clips. Easy to assemble and clean. Fun for pets and owners alike. Your imagination is the only limit. Perfect for mice, dwarf hamsters and juvenile hamsters. Measures 16-inch width by 9-inch depth by 8-inch height.