Nautilus Designs Severn Ergonomic Medium Back Multi-Functional Synchronous Operator Office Chair With Adjustable Arms Black - DPA1435MBSY/ABK DDModest, sturdy and reliable, this ergonomic medium back chair is host to a range of features which allow adjustment to suit the user's preference. A medium height contoured backrest with a 3D curvature incorporates lumbar and spine support. A multi set synchronous mechanism offers back height, back rake, forward seat tilt and seat slide adjustment. It also provides tension control adjustment to allow for the individual's bodyweight and is lockable in