This chair is AFRDI level 6 certified without arms only. It has gas lift height adjustment and ratchet height adjustable back and lumbar. It comes with high density polyurethane moulded foam seat and polished aluminium 5 star base. The independantly adjustable tilting back can be locked in any position or free floating. the independantly adjustable seat can also be locked in any positon or free floating. It is Ergocare TM certified. There is also the option of adjustable T arms. It has a full 10 year guarantee excluding upholstery.