High quality stereo sound Comfortable wear Good ABS material Foldable ... studying material2.Power supply: inlay rechargeable Li battery, use high efficient components, it can work more than 15h.3 ... TF card.4.Sound design: Use best horn, ensure HI-FI acoustic. Use best decode chip, WAV original sound decode ... shut off auto after 30s8.OEM are welcome High quality&best computer headset with TF card function