Brocraft Aluminum Downrigger Gimbal Mount With Low-Profile Swivel Mounting Base / Downrigger Swivel Base / Downrigger Swivel Mount For Boat Rod Holder .Made by marine grade T6 aluminum with CNC processing, Welding . fit boat 30 degree rod holder . Swivel Base made by composite components and stainless steel construction make the standard model as strong as it is versatile, designed to endure the roughest fishing conditions . Swivel base 16-point 360° swivel base that locks every 22. 5° for 360 downrigger rotation . Removes easily by pulling it up and out of your rod holder . Pre-drilled and tapped for easy installation ，Fit Cannon , Brocraft Downrigger