Wise 8WD013 Standard Pilot Chair & Pedestal Combo Features 8WP21-18S ABYC Class AD Driver Adjustable Pedestal with Seat Spider. Chair is Constructed with Thick Wall Rotational Molded Plastic Frame with Pre-Mounted Plastic Injection Molded Mounting Plate with T-Nut Inserts. Snap on and Off Cushions have High Compression Foam Padding with Mesh Underlay to Expel Moisture. UV and Mildew Treated Marine Grade Vinyl with Embossed Vinyl Surface and Embroidered Logo. Pedestal Features Polished Cast Aluminum 9" Base Plate with Recessed Knurled Mounting Holes. 2 7/8" Diameter Thick Wall Extruded Aluminum Post. Cast Aluminum Seat Mount Swivels 360 Degrees and Locks Down Tight.