Ram Mount Yoke Clamp Mount with Double Socket Arm and Diamond Base Adapter Consists of a yoke clamp base, standard length double socket arm and 2.43" x 1.31" diamond base The yoke clamp base will fit rails in diameter from 0.625" to a maximum of 1.25" The 1" rubber ball is at a right angle to the plane of the mount The diamond base has two holes 1.912" from center to center, matches the industry standard AMPS hole pattern Powder Coated Marine Grade Aluminum