Wise Baja 3315 series bucket seat with flip-up bolster features rotational molded plastic frame, high compression foam padding, UV, and mildew treated premium-grade marine vinyl. Double top-stitch construction. The bolster mechanism is high-grade aluminum construction. Universal mounting plate included. Mounts to virtually all 5 1/4" hole pattern marine pedestal systems. Universal mounting plate included. And mounts to virtually all 5 1/4" hole pattern marine pedestal systems.