Classic Replica mid back office chair BLACK Pleather - stabilizing swivel bar and knee tilt with tensioner knob. (Single Mid Back, Black) CH2801 Ribbed Black Mid Back Office Chair, back and seat with PU padding and backing Stabilizing bar swivel (360-Degree rotation), fully adjustable height and knee tilt with tensioner knob. Sturdy, heavy-duty pyramid chrome base White capped covered nylon wheels  slip resistant on most floors and carpets. Fire retardant foam  California standard CA117