Cannon Downriggers Low Profile Swivel Base Black. 5 degree . Composite components and stainless steel construction make the standard model as strong as it is versatile. Specifications for Cannon Low-Profile Swivel Base Mounting System: Manufacturer: Cannon Size: One Size Features of Cannon Low-Profile Swivel Base Mounting System Pre-drilled and tapped. Low profile design maximizes available space. Compatible with Universal Base and Tab Lock Base Package Contents: Cannon Low-Profile Swivel Base Mounting System Cannon Downriggers 2207003: Low Profile Swivel Base Black