... 5",marine pedestal seat,boat seat pedestal,high steel,EDC coating,fixed on 360 swivel base adjustable seat pedestal 11. ... 5"-17.5",marine pedestal seat,boat seat pedestal.height size: 11.5 ... 360° swivel base mounted on top for a complete seat mounting syestem. Great for Jon Boats and Canoes. ... 5"PIC 2 : Max height: 17.5" adjustable seat pedestal 11.5"-17.5"