The RAM-111B, universal mounting plate, consists of a 1.5" diameter rubber ball, connected at right angles to a flat 6.25 x 2" rectangular plate. The plate contains different combinations of pre-drilled holes which will match up to many electronic devices and mounts, including Marine GPS, CB Radios, Ham Radios, Gimbal Brackets and more. Material: Powder Coated Marine Grade Aluminium Ball Size: 1.5 Inch Rubber Ball