Springfield Marine EZ Ride Boat Seat Pedestal PackageFeatures: 3-1/2" of vertical travel; Intended for recreational inshore use; Tested to ABYC H31 dynamic static loads; 12" aluminum pedestal; 9" round base; 3-1/8" outer post; 2-7/8" inner post; 4 grooves with keys provide rotation lock; Keys restrict movement collar; Anodized finish; Uses a gas shock inside a mechanical spring; Wave dampening; Warranty: 5 Years Substrate/Frame