CoolerMaster Centurion doughnut looking thing in package

[MelonSplitter]

I just purchased this case and was stumped as to what this doughnut looking thing is. It is made out of maybe plastic and is colored grey. It is the size of a large life saver candy. What is this.

 

[Qtip42]

It usually wraps around the power button/power led/ reset button etc wires...... Nobody really uses them.

 

[filthysanchez]

it's called a ferrite donut.

 

[Arcygenical]

Basically, if you put your cable through the ring, and loop it a few times (so that it looks like the toroids on your motherboards... the round donuts with copper wire wrapped around them ) it will cut out any RF interference from going into the wire or coming out of that wire.

I guess it works, I've never used it for anything other than analog audio that get's disrupted by incoming text messages/calls from my cellphone (But now I dont know if someone's calling if my ringer's on silent ).