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On the power harness - one loop through the ferrite core.

Bronze

They are basically a ferrite material shaped like a donut and usually in a plastic housing. They are divided into two and basically snap into place around the wire(s). You can get them at Radio Shack, or better, do some research and select one or two for the frequency ranges that you want to protect (generally less than 1GHz, more like the 500kHz range up to the FM band). You've seen them before, just probably didn't realize what they were for. They typically look like a little fat cylinder on the power cord of PCs and/or printers. That's actually a choke. But depending on the material and grequency they are tuned for, they can vary in size. They will not affect the performance of the computer you've installed.