Adapter bracket that allows for mounting an C-MD Series & C-HDM-300 Series to a Gamber-Johnson center mount inner pole Gamber-Johnson center mount inner pole is different from the standard inner pole Universal adapter plate 1.26 inches high x 3.5 inches wide x 3.00 inches long Specifications: Material: heavy-gauge steel for rugged durability with black powder coat for anti-glare and rust prevention Gross Weight: 1.00 lbs Abbreviated Product Description: FXDADP, BRKT, KIT, DEVMT