I've been using these for about 3 months. I'm selling them because I no longer need them after buying a replacement. Operation has been confirmed. They work without any problems. I only used one type of ear tip, so the others that came with it are unused. There are no scratches or stains on the case or the earphones. Of course, everything has been disinfected with alcohol. The second generation was recently released, but I feel there's almost no functional difference. You can buy these for about half the price, so please consider them. Thank you.