Z300-C High Surge Wirewound Resistors Vishay / Draloric Z300-C High Surge Wirewound Resistors feature non-flammable cement coating, high-grade ceramic core, power ratings up to 6W, and high voltage surge (up to 12kV) for a special version. Z300-C High Surge Wirewound Resistors comply with Vishay Green Standards. Ideal applications include power supplies, energy meters, industrial and home appliances, and electronic ballasts.