Accepts 3/8 x 24 threaded antennas Die cast ball mount with lug connector. Use ring terminal coax cable with this mount. Base is 3.5 inches in diameter Ball is 2 inches in diameter Mounting screw holes are 2 7/16 inches apart from center to center Teeth on each half of the ball keep it from moving once assembled. Included backing plate provides added support Included rubber gaskets adds weather resistance Additional Model #'s 221-AUBALL AUBALL