Wise 8WD015 Pilot Chair with Arm Rests & Pedestal Combo - Thick wall rototional molded, high impact marine grade plastic external frame, includes a pre-mounted universal pedestal mounting plate with T-Nut inserts and a Wise 8WP21-18S adjustable height seat pedestal Snap-on cushions 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 marine environment conditions Pedestal is constructed of extruded and cast polished aluminum, with a thick walled, 2 7/8" polished anodized aluminum post; 9" diameter base with recessed mounting holes; Class AD certified per ABYC standards Pedestal is adjustable from 12" to 18" in height, simply pull and turn the height adjustment knob to raise or lower your seat; Cast aluminum seat mount locks and swivels 360 degrees with adjustment knob SEAT and PEDESTAL COMBO DIMENSIONS - Seat Height: 18.25" Width: 17.75" Depth: 22.5" Sitting Depth: 17" Sitting Width: 17" Overall Height with Pedestal: Adjustable from 30.25" to 36.25"