Shell in plastic composition with up to 25% wood fibers. Sled base is made from Powder lacquered steel.The wood fiber and plastic blend is injected into the mold, forming the chair's shell. Swivel piece is die-casted aluminum. Swivel foot is casted in one piece. Clean with a moist cloth. If necessary use a little dish soap on the cloth. For upholstery versions, please find cleaning instructions for your chosen textile at square. com or for leather at ca-mo.com. For leather upholstery versions: Clean the leather with a dry cloth regularly. Treat the leather at least four times a year using only special leather treatment products for aniline leather.