For the appearance, choose a magnetic ring with “as long as possible, as thick as possible, and as small as possible in inner diameter”. That is, the longer the magnetic ring, the better, and the tighter the aperture and the cable that it passes through, the better. However, in the case of DC or AC bias, there is still the problem of ferrite saturation. The larger the cross-sectional area of ​​the suppression element, the less likely it is to be saturated.
The magnetic ring has a conditioned reflection effect on electromagnetic waves, thereby reducing the distortion of signal transmission. The position of the magnetic ring is as close as possible to the end of the source (the inlet and outlet of the cable), which will more effectively suppress electromagnetic radiation.