RAM Rail Clamp Ball Base for 2" 2.5" Rails (RAM D 271U 2) (sku 55164) RAM Double U Bolt Ball Base for .75" 1" Rails RAM Mounts UK RAM Mount Dual Large Zinc U Bolt Rail Clamp Base With 1.5 inch Ball RAM RAM 2" 2 1 2" DIA. RAIL BASE W BALL LIZARD.LT RAM Double Ball Mount with Rail Adapter Base RAM Mounts UK. OVERVIEW The RAM D 271U 2, round pipe base, consists of a 2. 25" rubber ball connected that will connect to a pipe tubing diameter from 2" to 2. 5" in diameter. HARDWARE INCLUDED (4) 1 4" 20 x 1. 5" Screws (4) 1 4" 20 Nylock Nuts (4) Rubber Caps CLAMP RANGE 2" 2. 5" diameter BALL SOCKET SIZE D Size (2. 25") WEIGHT CAPACITY 6 lbs MATERIALS Marine grade aluminum PACKAGING TYPE Poly Bag WEIGHT 1. 22 lbs.