Here is Duke Snyder latest version of the Excluder. He calls it the Excluder II. The TW-12C martin house Excluder II adapter plate is designed to fit onto most houses to convert them to SREH. The present holes must be enlarged, and then, the adapter plate is attached by 2 screws. The plate measures 3 1/4" tall by 4 1/2" wide. The bottom of the plate is 1/4" from the bottom of the Excluder II. The TW-12C sells for $2.50 each plus S&H.