The RAP-B-347U base consists of a 1" diameter rubber ball connected at right angles to a 2" x 1.7" square base. The base has four pre-drilled holes at each corner, making the universal 1.5 x 1.188 (hole spacing) AMPS hole pattern.
Powder Coated Marine Grade Aluminum
B Size 1" Rubber Ball
The "U" in the part number reflects product packaged in poly bag.