W Series Wirewound Power Resistors Bourns W Series Wirewound Power Resistors have low thermal resistant ceramic cores, E24 resistance values, and a wide power range (1W to 10W). These resistors feature a coating material that meets UL 94V-0 requirements, ±300ppm/°C temperature coefficient, and 5% tolerance. Bourns W Series Wirewound Power Resistors are ideal for smart meters, lighting, power supplies, and renewable energy applications.