The Big Jon Vertical Gimbal Mounting Base is an easy way to mount any Big Jon product with a 4 inch square base. This mounting base provides quick and easy removal of rod holders and downriggers. This Vertical Gimbal Mounting Base easily slides into any gimbal holder and has a notched base to fit into the holder's pin, which prevents it from turning. Height: 12 in. Manufacturer's limited lifetime warranty The Big Jon Vertical Gimbal Mounting Base is made in the U.S.A.