Select from two types of backrests. The reclining models come with a double spring in that backrest that is absorbed. Backrest allows individual adjustment with the aid aid of depth and height adjustment of the backrest. With the semicircular design the backrest can be swiveled by 90° to the right of left side. It can also be mounted on the right or left side or in the center. The back rest can also be inclined backwards or forwards by 11° and the unit can be lowered to the lumbar vertebra area. There are three varying adjustment of the seating area, these are done to the height or sizes that are necessary for working 42-54 cm, 46-58 cm and 54-73 cm. Seat adjustment takes place with the assistance of a gas spring which operates as a hand leaver located below the seat. All units come with safety castors.