This mounting Adapter is for surface or track mounting, this smooth-action swivel base provides for 360 rotation, with 16 locking points spaced every 22.5. The top plate is pre-drilled and tapped for mounting all Cannon downrigger models. As a bonus, this unit also includes an aluminum mounting plate. This unit is not for the Cannon Mini-Troll which has its own mounting clamp.
I am also selling a Cannon electric downrigger unit, a Cannon Mini-Troll manual downrigger unit as well as downrigger weights. These can be found in my other posts.