5pcs 42X24X16mm Toroid Core,Ferrite Rings Toroid Core Iron (Black)

These toroids arrived promptly and were undamaged and as described. The size is good for thin coaxial cable and unterminated power lines. These did the trick to eliminate common mode current back into my transciever from a longwire on a 9:1 balun. I also have an air wound choke on the line which lowers, but does not stop common mode current, and which only reduces noice on part of the spectrum. The addition of this toroid to the feedline stopped the CMC and quieted down noise accross the spectrum.If you are looking for a toroid to use on 110ac wires with standard or grounded plugs you will need a larger size, these would be perfect for DC lines from your power supply.I am unsure of the mix, but will attemp to build a few baluns/ununs in the future and see how they perform. This is a great price and they are good toroids.

There was a lot of excess electrical noise on my Starlink conversion to 12v. These rings helped calm things down a lot. Now it performs much better.

Has worked well in each application in which it was installed -- primarily 2:1, 9:1 voltage baluns. I haven't tested it in choke applications. I will reorder when my inventory reaches zero.

Did what they are supposed to do.

Works well for RF choke

They work well but one was broken when I opened the package.....

Product is as advertised - nice size allowed for easy cable threading. Final solution to a unique problem was to slow a Fluke 8842a’s sample rate down to “S0” to turn on internal analog and digital filters.

I used this to wind 6 turns of a USB A to USB B type cable (usually used on printers) for a QDX ham radio 5 watt transceiver. I was having RF problems getting into the computer, and this solved it with no adverse effects on signal. A bit heavy for a light weight portable radio, but solid performance.