Cannon 1903002 Low-Profile Swivel Downrigger Mounting Base, Stainless SteelCannon Mounting Systems help rig the system in your favor. The Cannon Low Profile Swivel Base has 16 locking points that allow for 360 downrigger rotation with locking positions every 22. 5. Composite components and stainless steel construction make the standard model as strong as it is versatile. Also available in 316 grade stainless steel model for added strength and corrosion resistance. 16 point 360 swivel base that locks every 22. 5 for 360