WARE Critter Universe The Great Wall Critter Habitat ExpansionProvides the perfect view to enjoy small pets. Slide out tray for easy, hassle free cleaning. Comes complete with bottle, bowl and attachment hardware. Universally connects to other modular cage systems. Cage-n-tunnel locking caps keep your pet safe and secure. The Great Wall can be mounted on the wall or it can sit on the dresser. WARE Critter Universe The Great Wall Critter Habitat Expansion is a great way to expand your Critter Universe cage and provide extra living space. Ideal for mice, hamsters and gerbils..