Design and materials ESD Sintec is equipped with seat and backrest shells made from volume conductive plastic. The conductive quick-change upholstery means that you can tailor this ESD chair to create the look you want. The chair features a sturdy five-legged base frame with flat lines, which is made from sectional steel tubing. This offers great stability as well as highly reliable electrostatic discharge. All ESD Sintec models are supplied with a black frame.