The RAM 1.5" Double Socket Arm is a mounting solution for the Motion Mobile Dock used with the RAM 1.5" Ball Mount. This standard, double socket arm has a socket at both ends that accommodates 1.5" ball bases. A single spring inside the arm opens the end sockets, allowing you to pivot the ball and socket connection. This socket technology allows for almost infinite adjustment and perfect viewing angles. SKU 507.051.21