Meet the Fatpets Cat Tunnel Bed: a clever cat cave made of recycled cardboard that gives your pet a place to nap, relax, and sleep. It measures 24.5 x 24.5 x 10 inches. This cat cave is suitable for kitties up to 20lbs. These can be used as a scratcher too.
The Fatpets Donut Cat Tunnel is selling for under $40 at the time of this writing.