Vista 24 Hour Blue Fabric Posture Office Chair. Upholstered ratchet back which moulds around the shape of the user’s back, for supreme thoracic comfort. Inflatable lumbar support means the user can adjust level of support throughout the lower back. 2-dimensional adjustable arms included as standard. Heavy duty asynchro mechanism, allows the user to adjust the seat and back independently as required. Integral torsion control to adjust torsion according to the user’s weight. Integral seat slide allowing adjustment based on the height of the use. Classic five star base.