RAM Long Double Socket Arm for 1.5" Ball Bases The RAM-201U-D, LONG 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. Dimensions: Overall Length: 9.125" Socket-To-Socket Length: 8.75" Material: Powder Coated Marine Grade Aluminum Ball Size: 1.5" Rubber Ball Size