The Coates Base Plate Adapter fit ANY of the Coates purple martin poles.
Included with the purchase of any of the Coates purple martin bird houses, this adapter makes it possible to install any other aluminum martin house on to a Coates telescopic pole.
You do not need an adapter to mount a martin house on to a multipurpose (Hybrid) pole.
Outer diameter of flange is 1-1/2" and inner diameter of flange is 1-3/8".


OD of 1-1/2" and an ID of 1-3/8" with 1/16" wall. There are two bolt holes to secure the pole to the base plate. The steel plate is used to attach any Coates/Watersedge House product to the Coates pole, or any pole with an OD of 1-5/8" to 1-7/8"; any pole with an ID of 1"; to 1-1/4"; will also work. The heavy duty pole top section (CHD12) fits over the outside of the adapter. NOTE: This base plate is included with the purchase of a Coates or WaterEdge house.