High-density resilient sponge cushioning provides a very comfortable seating experience that not only promotes relaxation but also helps dissipate stress. Proven by extensive ergonomic research and testing, the backrest is cleverly shaped to 15° to match the natural contours of your spine. This design element provides excellent support, protects the natural curvature of the spine and ensures a comfortable, fatigue-free seating experience, even when sitting for long periods of time.