Provides an adjustable mounting platform for fish finders or chart plotters with U-shaped brackets. Mates to StarPort, StarPort HD, SidePort, Rail Mount, RIBPort, and E-Series USB StarPort bases (not included). Dimensions: 6-1/4" X 2-5/16" (platform surface). Accommodates fish finders and chart plotters up to 3.3 lbs.Fits most fish finder brands