RAM Mount Double U-Bolt Rail Mount w/Round Base [RAM-101U-235]RAM 1. 5" Diameter Ball Rail Mount w Double U Bolt Base & 2. 5" Round Base (AMPs Hole Pattern The RAM 101U 235 consists of a double socket arm, one round 2. 5" diameter round base with the universal AMPS hole pattern and stainless steel double u bolt base that will fit pipes from 1" to 1. 25" in diameter. Designed into the mount is a 1. 5" diameter patented rubber ball and socket system with adjustment points at both socket ends of the arm. Rubber