Wise 8WD1007 Captains Chair & Cushions and Pre-Mounted Universal Mounting Plate with T-Nut inserts. Mounts to any 4 Bolt BIA Standard Pedestal System Thick wall rototional molded, high impact marine grade plastic external frame, includes a pre-mounted universal pedestal mounting plate with T-Nut insert Snap-on cushions and arm rest pads with compression foam padding and mesh underlay to expel moisture; Features embossed vinyl surface detail and embroidered logo Heavy Duty Marine grade 28 oz. vinyl withstands the effects of sun, heat, rain and soiling under normal conditions SEAT DIMENSIONS - Height: 21" Width: 17.5" Depth: 24" Sitting Depth: 15" Sitting Width: 17"