This unit is designed to slide into a flush mount and allow you to slide any rod holders, downrigger mounts, or other accessories into this track. The added feature of a track on the gimbal offers an expanded area; this can be used for additional equipment when fishing multiple setups. The uniqueness of adapting fishing equipment to this gimbal mount allows for quick and easy installation. When not in use it can be removed to return the boat to its original condition. Boats that are 30 feet and under are factory equipped with flush mounts that use a 30 degree 1 1/2" dia. x 10 1/2" long tube gimbal mount. This is the most popular in sizes on the market today. The 18" track will accommodate up to 3 rod holders or 1 rod holder and a downrigger base.