"Take bumps and jolts out of your ride with the AirWave Pedestal Shock-Absorbing Boat-Seat Pedestal. The AirWaves patented system uses a Goodyear airbag, supporting riders from 20390 lbs. and letting you fine-tune your personal comfort settings with the simple use of a hand air pump. The pedestal has 2"" of progressive rate travel. Proprietary technology provides the rider with innovative, controlled up-and-down motion, giving the rider the most comfortable ride through rough water without excess bouncing or the feeling of being catapulted. The AirWave Pedestal is compact, durable, and dependable with a weight of 11.5 lbs. Performance-grade, anodized aluminum and stainless steel material ensure years of rugged dependability. The AirWave Pedestal uses a 2-7/8""-dia. upper aluminum tube. For easy installation, the bottom base uses a 6-hole, 8-dia., marine-standard bolt hole pattern.Manufacturer model #: AWP522. Uses Goodyear airbag for reliable, customizable comfort Supports riders 20390 lbs. Lets you fine-tune your personal air settings 2"" of progressive rate travel No more excess bouncing or feeling of being catapulted Anodized-aluminum and stainless steel construction 2-7/8""-dia. upper aluminum tube 6-hole, 8-dia., marine-standard bolt hole pattern"