Swivl-Eze Wedge Base - 9 Brushed Aluminum Attwood Wedge Bases are built strong with reinforcing ribs and an improved profile to withstand the toughest conditions. Bead blasting closes aluminum porosity and the brushing process provides long-lasting, high-sheen finish. Specifications ABYC Code AO - Type AOperator OK for HelmDriver position Required Diameter Mounting Hole 3.25 Depth below deck 2 California Residents WARNING Cancer and Reproductive Harm - P65Warnings.ca.gov Other Details Google Pro