Ergonomic design with an S-shaped backrest to curve around the spine and provide better support.The X.44 mesh operator chair has a unique s-shape design to provide comfortable working while sitting. Includes lumbar support, adjustable headrest, adjustable armrest and seat height adjustment. Assembly required - Yes Assembly level - Easy, under 15 minutes Seat slide adjustment - No Height adjustment - Yes Mesh back - Yes Weight balance - No Lumbar support - Yes Adjustable armrest - Yes, 3D adjustment Headrest - Yes Back position locking mechanism - Yes, 3 Stage Tilt Adjustment Back material - Mesh