Lemeng (6-PACK)Diameter3. 5mm 7mm 9mm Detachable Magnetic&nbsp;Anti-interference Filter Ring Material: Nickel zinc ferrite Wire Diameter: 5mm 7mm 9mm Item color: black. Widely used in color TV, mobile phones, monitors, electric car chargers, alarm, DVD, switch power supply, the UP power supply, DC - DC converters, high frequency transformer, filter, inductor, household appliances, industrial automation, instrumentation, communications, medical equipment, energy-saving lamps and lanterns,etc. Packing:6pcs