Flex back       Flex back is equiped with a MINISYNCHRON mechanism, which can be locked in 5 positions with anti-kick backrest and adjustable tension control. But the main feature of this chair is the extemely flexible and indeformable foamed backrest, which gently allows for any movement of the user, from the seating position ( see animation ). Furter options are the adjustment of backrest height with UP & DOWN mechanism simply placing hands under the backrest and lifting it up, arms adjustable in height and side, polished aluminium 5 stars base with gas seat height adjustment and type W castors (nylon/self-braking).