The Atlanta Communities 24 Aluminum Slidein Plate for the Wood Armpost is a heavy-duty arm post designed for safety and security. It has a one-piece cast aluminum sleeve that slides securely into the wood arm post. Features include a 3-5/16” x 10-1/4” mounting plate, four lag screws, and a rubber cap to keep debris out. It is corrosion resistant and has a powder-coated finish for durability. This slide-in plate is the perfect solution for any residential or commercial applications.