The RAM-B-101KRU consists of a double socket arm and two 2.5″ diameter round bases that contain the universal AMPS hole pattern. 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. The hole pattern found on the round base adapter will connect to many RAM cradles, including all iPad cradles. The included RAM’s patented design dampens shock and vibration, helping to extend the life of your device. RAM double socket arms with their distinctive Hourglass Shape are designed and recognized to provide the best possible performance for most any application. The Hourglass Shape is a registered trademark of National Products Inc.