Attwood Avenir Bolster Seat Off-whitered . Comfort Boaters have been Demanding Avenir is the worlds first bolster seat with the award winning patented SAS shock absorbing system. Attractively patterned Avenir SAS spring suspension seats are trimmed out with a backrest upholstered onsert for deep-tuck styling and molded polyurethane foam with stapled-in-place upholstery. All upholstery is marine-grade vinyl. Seats include corrosion-resistant T-nuts for attachment to seat pedestals. Seat Shell and Molded Foam Work together to provide ergonomic comfort and spinal support Quad Spring Suspension Provides comfort and 3 travel for shock absorption. Prevents rider from bottoming out. No Exposed Hinges No ugly brackets or fasteners to color-match pinch or abrade.