Wise 8WP145 Heavy Duty Mainstay Air Power Pedestal with Locking Swivel and Slide Air Powered Height Adjustment from 14.5 in. to 20 in 2 7/8" Diameter Post, 9" Anodized Base Locking Seat Mount with Fore & Aft Slide Perfect for Saltwater Helm Seat Applications 3 Year Warranty