The RAM-111-247-2 with square rail clamp base, consists of the 1.5 inch diameter ball and socket system with RAM universal rectangular 6.25 x 2 inch base. This mount is designed to be a universal mounting solution for large and heavy electronic devices, including GPS, CB Radios, Ham Radios and more. The hole pattern found on the rectangular base will connect to a large variety of third party holders, gimbal brackets and mounts. The mounting base is a perfect solution for mounting to the cabin frame work on a fork lift, or any other square post up to 2 inches square. Material: Powder Coated Marine Grade Aluminium Ball Size 1.5" Rubber Ball Size Colour: Black Components RAM-111B RAM-201 RAM-247-4