Garelick Adjustable Height Seat Bases - Smooth Finish Features Seat raises or lowers, locks at desired height 4 prong spider swivels 360 and locks Available anodized finish which helps prevent saltwater corrosion and weathering 2 78 7cm diameter smooth stanchion tube, 9.25 23cm diameter base plate Specifications 75035 Polished 12 - 17 30 - 43cm High 75235 Anodized 12 - 17 30 - 43cm High Instructions Mounting Instructions California Residents WARNING Cancer and Reproductive Harm - P65Warnings.ca.