The RAM-B-201-C-KRU, long double socket arm, has a socket at both ends that accommodate 1" 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. The knob has a locking Acorn nut that prevents the mount from being removed from the socket. This Feature allows for a secure mount while giving the ability to adjust your device without the ability to remove the device.