RAM Mount Long Double Socket Arm w/2.5" Round Base [RAM-B-103U-C]RAM 1" Diameter Ball Long Double Socket Arm with 2. 5" Round Base that contains the AMPs Hole Pattern Overall Length: 6. 62" The RAM B 103U C consists of a 2. 5" round base and LONG double socket arm that will accept 1" ball bases. The round base contains pre drilled holes, including the universal AMPS hole pattern. Designed into the mount is a 1" diameter patented rubber ball and socket system with adjustment points at both ends of the socket arm;