Cannon 4 In. AlumInum Fixed Base Pedestal Mount 4in. The top plate is pre-drilled and tapped to allow mounting of a Cannon swivel base and downrigger (and other downrigger brands). Specifications for Cannon AlumInum Fixed Base Pedestal Mount: Manufacturer: Cannon Color: Black/White Length: 4 in 6 in Features of Cannon AlumInum Fixed Base Pedestal Mount Pre-drilled and tapped. Constructed from high-grade aluminum. Accepts most downriggers. Package Contents: Cannon AlumInum Fixed Base Pedestal Mount Cannon 1904030: 4 In. AlumInum Fixed Base Pedestal Mount 4in