Resistick IIâ„¢ coated blade, ball and needle electrodes are expertly coated with PTFE (polytetrafluoroethylene). They move more effectively through tissue because they resist eschar build-up making them much more efficient during surgical procedures. Unlike the common stainless steel electrodes with a propensity to accumulate the discarded blood and tissue, Resistick IIâ„¢ coated electrodes simply wipe clean.- Ball Electrode, 2", 4mm Dia, 12/bx 14-21 Days