ESR tape/fabric is a material embedded with different materials, like carbon fibers, which is designed to absorb EMI/RFI, sort of like a fabric faraday cage.
(if you wrap your cell phone with it, the phone will lose most if not all of it's signal strength)
The place we used to get it from stopped selling it commercially as they wanted to start using sheets of it in other products they sell, but they still had several 2" wide rolls that they didn't have any use for, so we bought every roll they had.
In our DIY speaker cables, we place a small strips of it at each end where the braided section of the cable is separated out into the two legs. it just helps to maintain the noise rejection where it is most vulnerable.
We sell it at $1 per inch.
Reach out to us at info@gr-research.com
