Review on Topnisus [Pack Of 10] Clip-On Ferrite Core Ring Bead Anti-Interference High-Frequency Filter RFI EMI Noise Suppressor Cable Clip (3Mm Inner Diameter) by Anthony Hales

It didn't work for my application but I still give 4 stars - they are well made. The description and picture are a bit misleading, "(diameter 3mm/5mm/7mm/9mm/13mm)" and the picture gives the impression that you will receive a set of different sizes. I noticed this discrepancy and inquired, and the seller gave an accurate answer (I bought them anyway, mostly by mistake; I will use them for other purposes). It's actually 10 identical (small!) parts with an internal diameter of 3mm - suitable for something like headphones or a USB cable, maybe small DC cables; but nothing more than that.