Ultimate heavy duty chairs to suit every user Physio approved Certified for 24 hour use (BS 5459-2:2000) Upholstered ratchet back which moulds around the shape of the users back Supplied with height adjustable arms Inflatable lumbar support, adjust level of support throughout the lower back Heavy duty asynchro mechanism, allows the user to adjust independently as required Integral torsion control to allow full control, according to the users weight Features a class 4 gas lift Five star base as standard Medium fire retardancy Finished in charcoal 2 year warranty