Five-spoke base in polished aluminum alloy with wheels or feet. Adjustable seat height. The tilting back, with controls, can be set in five different positions or made to constantly rock. Self-extinguishing polyurethane foam upholstery with elastic strip springing. Seat cushion in polyurethane/Dacron Du Pont, on request. Non-removable internal nylon cover. Removable external fabric or leather cover.