Cylindrical shaped magnetic ring magnetic pass absorption magnetic ring/magnetic beads more unit line cable Shang of EMI interference inhibit, including power line Shang of noise and pointed peak interference, it while has sucking EMI absorption magnetic ring received electrostatic pulse capacity, makes electronic equipment reached electromagnetic compatible (EMI/EMC) and electrostatic discharge of corresponding international standards, using Shi can will a root more core cable or a beam more unit line cable wear Yu which. more wear once can strengthening its effect. Usually 25MHz and the impedance values measured absorption characteristics of the magnetic ring magnetic beads.