Wise 8WD562 Ladderback Helm Chair is Constructed with Thick Wall Rotational Molded Plastic Frame with Pre-Mounted Plastic Injection Molded Mounting Plate with T-Nut Inserts. Aluminum Back Support Back Brackets. 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. Padded Aluminum Arm Rests. Mounts to any BIA Standard Pedestal System.