The RAM Adapt-A-Post™ Quick Release Track base is available to mount the full line of RAM Post and Spline rod holders, for your heavier fishing rod set-ups. The post portion of your fishing rod holder can drop into the Adapt-A-Post™ while facing any direction, and to remove, simply press the side button of the Adapt-A-Post™ and your rod holder lifts right out with ease.This kit comes with three different flat plates for hard-mounting onto your boat or kayak, depending on the footprint shape and hole pattern. The round plate is 2.5" in diameter and contains the 4-Hole AMPS hole pattern. The diamond plate is 2.5" x 1.3" with the 2-Hole diagonal AMPS hole pattern, and the rectangular plate is 1.7" x 2" witht the 4-Hole AMPS hole pattern.