This is the Hole and One Shelf piece of cat furniture. It is great for 1 or 2 cats. It has a 16 x 19" base that has two 36" tall legs on the sides. Between the legs is a small tunnel that has a 9" inside diameter, resting on top of that is a 13" inside diameter larger tunnel. That tunnel is 12" wide. On top of the 36" legs is a 24" long saddle shelf, great for sprawling out on. Comes in neutral color unless specified. ASSEMBLY REQUIRED. Instructions and hardware included.