attwood Centric SAS Fully Upholstered Highback Boat Seat Centric SAS builds on the appearance, dimensions, and ergonomic features of the Centric seat. It stands just 2" taller than the correspondng Centric seat. Incorporates all of the ergonomically tuned comfort surfaces of the Centric seat with the added comfort of the SAS shock absorbing system. In rough seas and tight maneuvers, the side bolsters and SAS suspension help to keep the boaters centered in the seat. All upholstery is marine-grade vinyl. Seat includes corrosion-resistant T-nuts for attachment to seat pedestals. Available in a variety of colors.So it's easy to use both Centric SAS and Centric seats on the same boat by adjusting the pedestal to match seat heights.