Cannon Mounting Base Magnum/Digitroll Lexan Black. Provides strong mount while also allowing easy removal of downrigger. Specifications for Cannon Standard Mounting Base: Manufacturer: Cannon Size: One Size Features of Cannon Standard Mounting Base Corrosion and UV resistant. Material: Composite Compatible with all Optimum Magnum Uni-Troll and Easi-Troll models. Package Contents: Cannon Standard Mounting Base Cannon 1904040: Mounting Base Magnum/Digitroll Lexan Black