ElectroChem offers a wide variety of pre-cut and bulk gasket material. The low precision silicone gaskets are sufficient for typical PEM fuel cell research. The thickness tolerance is +/- 2 mils, so proper thickness selection is critical. The high precision silicone gasket is similar, but has a thickness tolerance of +/- 0.5 mils. The Teflon and fiberglass reinforced Teflon are used in high temperature applications such as phosphoric acid fuel cells.