Infinitely adjustable seat height with top lift. This model bears the GS mark from LGA Nürnberg and meets all safety-related requirements for office and object areas according to DIN EN 1335 Part 1-3. Ergonomically shaped backrest with an integrated, elaborately padded comfort headrest. Comfortable, extra heavily padded seat with a contour shape. Upholstered in genuine black leather with intricately stitched white double seams, the back and side panels are made of matching synthetic leather. Kinematic rocking mechanism, with spring force individually adjustable to body weight. Aesthetically pleasing and stable polished aluminum base. Equipped with load-dependent braked safety dual castors for carpeted floors. This means the chair only rolls under load; when not in use, the castors brake to prevent unwanted movement. Includes armrest "F2". This item is delivered unassembled. Assembly can be completed in a few simple steps. No assembly is required for gas springs, chair castors, footrests, etc.