This unique Taper-Lock pedestal system allows a pedestal to be removed from its base and yet remain firmly in place when required. The slightly tapered Delrin bushing allows the pedestal to fit snugly, yet disengage as needed. Locking tab helps prevent the pedestal from turning and keeps it firmly secured. When you remove the pedestal, Taper-Lock becomes a "Hi-Lo" system which allows the seat to be used down in the lower position while the boat is under way. Pedestal shaft is 11". Overall height including the bushing at the bottom is 13".