ESD-R-28C-1 - 

The ESD-R series Toroidal Core is designed for use on round cable. A wide range of MnZn and NiZn options are available in bare, coated and case types. There are two ferrite material options for KEMET EMI cores such as nickel-zinc (Ni-Zn) and manganese-zinc (Mn-Zn). Each core material has a different resistance and effective frequency range. The Mn-Zn core material has lower resistance compared to the Ni-Zn, therefore, be sure to provide adequate insulation before use. For reference, the Ni-Zn core material is typically effective for the frequencies in the MHz band range such as the FM-band, while the Mn-Zn core material is typically effective for the kHz band range such as the AM-band.