These cores of ferrite avoid high-frequency interference, to which ribbon cables in particular are very susceptible. Due to the physical construction, there exists high capacitive coupling between the individual wires of a ribbon cable. The effects of this are evident on analogue and digital signals, and not only in terms of crosstalk. Such a cable can act as an unintended antenna even at a range of a few centimetres. Cores for ribbon cables provide a remedy for this. They can be precisely fitted to a ribbon cable when the cable is being made up.