Cannon Rail/Side Mount Downrigger Black. Machined aluminum construction powder coated to resist corrosion. Specifications for Cannon Rail/Side Mount Downrigger: Manufacturer: Cannon Size: One Size Features of Cannon Rail/Side Mount Downrigger Perfect mount for "T" joints on rails or narrow gunwales. Adapts to tubing up to 1.5' or 40mm Compatible with all Cannon Downriggers (except Mini-Troll) subject to the strength of the tubing it is mounted on Package Contents: Cannon Rail/Side Mount Downrigger Cannon 2250940: Rail/Side Mount Downrigger Black