The Double Diamond has a 24 x 24" base. It has (2) 18" lower legs, and (2) 30" tall back legs. Sitting on top of the lower legs is a 24" long tunnel that is open on both ends and has 2 diamond shaped windows in the front. Fully carpeted tunnel inside. On top of the tall legs in back is a 24" long saddle shelf that is 14" wide. A nice solid piece for 2-3 cats. Comes in neutral color unless specified. ASSEMBLY IS REQUIRED. Instructions and hardware included.