Back of chair will not stay at set height.  Mechanism uses hand screw to friction hold in place and isn't strong enough.  every few days chair back just keeps sliding down.  quality is marginal.  assembly was simple  lumbar support is minimal and included lower pillow is subpar in how it attaches to the chair.  leg extension only has a stop on one side via a set screw and the entire assembly could due to extend another 4" to be beneficial.