The RAM-B-189B-201-ALA1-KRU consists of a double 3.3" twist lock suction cup base that is connected to the diamond base with 1" rubber ball. The suction cup is designed to have an extra strong hold on any smooth non-porous surface, but for best result, mount the suction cup on a glass or non-porous plastic surface. The ball on this base connects to the standard length double socket arm with retention knob. A single spring inside the arm opens the end sockets, allowing you to pivot the ball and socket connection. The knob extension allows for easy adjustment of the mount and prevents over loosening of the knob. This socket technology allows for almost infinite adjustment and perfect viewing angles.