Bone conduction wireless headset. Purchased three years ago, but only used a few times indoors, so it's practically new. Comes with the box, dedicated case, charging cable, and instruction manual. The manufacturer's warranty period was two years from purchase, so it has expired. I have confirmed that it works without any problems. I bought it for approximately 23,000 yen, and I'm selling it for half price, 11,500 yen.