The Big Jon Downrigger Gimbal Mount fits all Big Jon dowriggers that have standard 4 inch bases. These 12 inch gimbal mounts feature heavy-duty aluminum construction with a durable black anodized finish for protection in all freshwater and saltwater marine environments. These mounts allow for use with existing gimbal rod holders. The Big Jon Downrigger Gimbal Mount is Big Jon Model GM46. The Big Jon Downrigger Gimbal Mount is made in the U.S.A.