Provides an adjustable mounting platform for fish finders or chart plotters with square or round bases. Mates to StarPort, StarPort HD, SidePort, Rail Mount, and RIBPort bases (not included). Dimensions: 4" x 4" (platform surface); 5-1/2" (height with mount arm). 3-Axis mount has "R-Lock" locking friction joints at top and bottomCenter joint is fully adjustable in 15° incrementsAccommodates fish finders up to 3.3 lbs.Mount on angled surfaces and keep your display level