- A range of ferrite rings & beads designed to cure electromagnetic & radio frequency interference at source Always choose an internal diameter close to that of the cable or wind through several times. Always put ferrites at the noisy end of the cable. The smaller ferrites Order codes N88CU N97AB & N98AB are supplied in packs of 10 whilst the other larger sizes are supplied singly. Order Part Max Max Min Attenuation Omega Codenumberdiameter mmlength mmhole dia mm 25 MHz 100 M Hz N88CUHEM30254.25.31.8528 51N97ABHEM30205.218.42128 147N98ABHEM30216.218.43100 155N48FKHEM302416.2814.677.5774 117N92ABHEM301514.629.16.05164 255N91ABHEM301416.0529.176.69164 258N87ABHEM301031.822.7518.588 146N90ABHEM301328.9629.3313.37158 250N88ABHEM301125.613.415.553 97QT26DHEM301636.87.324.423 63