The Onyx chair is a fresh, contemporary office chair that offers a range of inspired features such as a multi-functional asynchronous mechanism with multiple adjustments and a contoured foam seat and back for extra support and comfort. The Onyx is a top choice for a posture task chair. Contoured foam seat and backrest for maximum user comfort Triple lever multi-function mechanism Ratchet height adjustable backrest Pump up lumbar support Seat slide Height adjustable arms Brushed aluminium 5 star base UK crib 5 foam and fabric Gas lift tested up to: 150 kg Usage: 24 hours