office chair Active, high backrest with ergonomic shape, adjustable headrest, synchronous mechanism with travel limitor, unique seating system: backrest is sliding in supporting frame and backrest curvation makes genuine lumbar support and provide optimum comfort to user, seat depth adjustment, grey plastic back backrest cover, black nylon backrest supporting frame, aluminium holder of the backrest and armrests in N2 finish, black nylon base, big castors with 60 mm diameter, pneumatic lift (price does not include armrests)