The RAM universal plate has a 1.0" diameter rubber ball connected at right angles to a 1 1/4" x 2 1/2" diamond plate. 

The plate has two holes 1.912" from center to center, positioned at either tip of the diamond plate. 

This base plate will attach to any of the RAM plastic HOL holders and fits the industry standard AMPS hole pattern. 

Powder-coated Marine grade aluminum.