Review on VSKEY Clip-on Noise Filter [10pcs 13mm]: High-Frequency Ferrite Core Choke for Subwoofer, Amplifier, Speaker, Video, Radio, Home Power Audio Device Coaxial Cable [0.5 inch Inner Diameter] by Cara Ruiz

All snap ferrites (with one exception) (have minimum specifications. You must specify at least (1) maximum current to saturation ( where the EMI filtering disappears) and (2) either the effective frequency range or the material (where you can look at the frequency range) Yes, they're cheap compared to other sources, but that sucks if they're going to do anything - this is good for filtering out conducted EMI. As you can imagine, for my application (filtering 180-200MHz in the cable that runs the cable from the solar panels to the inverter) they didn't do Jack C.