Cardboard Castle Tunnel is available in 5 sizes to cater to the comfort of your beloved small pet. Our Guinea Pig Haven is pictured in the Large size. Available in 5 sizes. Small - 7 inch x 3.5 inch x 4.5 inch - Door 2.8 inch x 2.8 inch Medium - 9.2 inch x 4.5 inch x 6 inch - Door 3.7 inch x 3.7 inch Large - 11.5 inch x 5.7 inch x 7.5 inch - Door 4.7 inch x 4.7 inch X-Large - 14.5 inch x 7 inch x 9.3 inch - Door 5.9 inch x 5.9 inch XX-Large - 18.2 inch x 8.7 inch x 11.7 inch - Door 7.5 inch x 7.5 inch Flat Shipped - Assembly is required.