Ergo seats have aluminum profile frames, open cell polyester foam paddings and water resistant, PVC-covered artificial leather upholstery. Ergo 505 and 808 seats feature a groundbreaking innovation, the patented Ergo-TRIFLEX seat bottom. - ergonomically designed - flexible - soft - breathable - prevents condensation from building in the seat cushion - prevents water from gathering in the paddings - prevents mold growth - absorbs vibration