Widely used in power , current sensors, , inductors, chokes, ballasts, voltage regulators, welding , broadband , filters and so on. This is a ferrite ring, not a magnet. It has no magnetism. It has the characteristics of isolating eddy current, low permeability and restraining interference. Iron powder cores are generally stored near the signal. You receive 34 pieces of iron powder core magnetic rings, which can meet your needs., Manufacturer: Mcnhbdgg