I got 3 of these brand new off mercari for 25.00 bucks 5 months ago. Sounds pretty damn good. One flaw that I haven’t experienced ( But heard) if you bend the cable too much, it will eventually cause the sac to stop working. So I use mine on my iPhone 13 Pro Max with one of those cell phone rubber net things, so it sits completely flat on the back of my phone. Oh, and you probably already know by now, that’s the hole isn’t a mic, but the led light for the sound quality.

all that and you didn't say how it sounds? and what headphone (impedance) you can use with it.