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

One can never have too many ferrite ring cores. There's always some device that is suffering from RFI and these work well to limit it.

Surprisingly useful, and delivered in a timely manner

These are great! Snap them on and done. See my picture for exactly what was in the box, as I'm not sure if it matches the description but seemed pretty close. I've written the sizes on them in the pic if you look close. The 3mm are good for regular car wires, which I used on my headlight wires at the bulb, the larger ones are good for covered cables, as well as smaller wires if you want to try looping them thru a couple times or more. They snap on easily and with a small screwdriver they are easily removed, yet seem to be quite secure when attached. Would buy these again.

A while back I bought an S-video cable for my old Nintendo Wii, which I have hooked up to a CRT television. I began to notice some noise and after eliminating the TV, the Console, and the Video switcher as suspects, I began to suspect the cable itself was at fault. I had seen that someone else had used ferrites on theirs and ordered this package and after putting 5 or 6 along the cable the noise is completely gone. The selection of thicknesses was perfect for me, as the Wii cable is thicker coming from the console, but splits into thinner cables. Every part of the cable was snugly accounted for. After experimenting with the Wii, I turned my attention to my Japanese Famicom. Japanese TV signals actually use the same range of FM radio frequencies that American radios do, and I sometimes could hear the local station whenever I turned off my system, and sometimes atmospheric conditions woudl generally just make the signal a mess. I put 4 of these along the cord of the RF adapter that goes from the system itself to the gray box (I use a North American RF adapter from the NES to hook mine up) and not only did the Radio interference go away, but the picture was a little cleaner (though RF will never be purely clean, that's just how that format is). All in all, this is an excellent package and a great value! I plan on buying more.

They worked as stated but they break if you squeeze them to get them to close and snap together. I had a couple break because it was hard to get them to latch properly.