20Pcs Clip-on Ferrite Ring Core Ferrite Bead RFI EMI Noise Suppressor Cable Clip for 3mm/ 5mm/ 7mm/ 9mm/ 13mm Diameter Cable, Black

work great

These helped reduce the amount of RF going into my jeep’s radio.

Bought these to suppress high frequency interference in an electrical system but for my particular issue they did not help so I cannot comment much, a few of the magnets were damaged from apparent rough handling

Used in .any applications where RF energy couples to power cables Great quality and consistency

I'm using this on a video cable from my MacBook to an external monitor, as I have rare events of the screen flickering. 2 months after installing it, I only had one flickering event. It might be too early to tell if this has reduced those events, but obviously it hasn't stopped it 100%.

they work very well sometimes may need to use 2 or 3 on line

Came in handy , used it on my new TV antenna. I'm near cellphone towers causing interference.

I purchased these on a recommendation to solve a persistent 'phantom connection' issue I was having with an old external hard drive. The drive was behaving erratically, constantly connecting and disconnecting. To my surprise, these completely fixed the problem! ​The connection is now perfectly stable. I have a lot of cables in a small space, so I'm sure I was dealing with electromagnetic interference (EFI), and this seems to have solved it. Since the pack came with extras, I put them on my other wires, too, lol