Modern Black Ergonomic Chair Good old Duorest recipe now in a modern design with Synchronized self-adjusting tilt movement. With a unique “Smart Dial System”, it is easy to adjust both the backrest’s Depth and Height. With D2’s simplified mechanism, you can easily optimize your comfortable sitting posture. Armrest, Headrest, Seat depth and Backrests, everything is adjustable. We recommend our Duorest 2.0 model for people who have a sedentary job or have to sit for a long time.