8WD1007 Captains Chair Features Rotational Molded Thick Wall Plastic Seat Frame with T-Nut Mounting Inserts. Snap On and Off UV and Mildew Treated Marine Grade Vinyl Cushions with Mesh Underlay to Expel Moisture. Embroidered Logo. Molded Arm Rests with Cushion Pads. 8WP23-15-374 15 Fixed Height Pedestal with 5 Travel Fore and Aft Slide. Features 9 Diameter Polished Aluminum Base Plate, 2 7/8 Thick Wall Post. Seat Mount Swivels 360 Degress with Locking Mechanism. Comes with Injection Molded Plastic Mounting Plate Pre-Mounted to Seat Frame. Seat Dims; Height 21, Width 17 1/2, Depth 24, Seat Depth 15.