Feature:1. IEM MODE: By connecting with a 2.4G receiver, it can realize remote sound IEM with almost no latency. 3.5MM interface is compatible with most of the sound cards on the market.2. STABLE CONNECTION: Adopting a new generation of intelligent chip, the listening receiving distance reaches 20 meters, realizing long distance recording and receiving. It has strong anti interference ability and stable signal without lagging.3. COMFORTABLE TO WEAR: Adopting ergonomic design, it is not only fashionable in appearance, but also compact and portable. Lightweight design with silicone skin friendly material makes it comfortable to wear and painless to wear for a long time.4. BT CONNECTION: The headphones also support BT connection. It can be used as a wireless headphone after connecting to cell phones and computer devices. It adopts premium sound generating unit, which is optimized by the professional tuning team to make the sound quality more excellent.5. MULTIPLE DEVICE EXPANSION: The receiver supports up to 8 headphones for joint listening. You can purchase multiple headphones and connect them with just one receiver, suitable for stage performances, studio recordings and more.6. SUPERIOR LONGEVITY: The headphones and receiver use high capacity batteries with a low power chip, which can be used continuously for 10 hours after a full charge. It also supports charging while using, which will not interrupt your rhythm.Specification:Item Type: Neckband HeadphonesMaterial: ABS, SiliconeDAC Output: 24bit Calculation, Signal To Noise Ratio 101dbDAC Input: 24bit Calculation, Signal To Noise Ratio 92dbSpeaker Caliber: 14.2mm / 0.56inSpeaker Impedance: 32Microphone Caliber: 4mm / 0.16inMicrophone Impedance: 2200Headphone Battery Information: Lithium Ion Battery, 200mAH (Built In)Receiver Battery Information: Lithium Ion Battery, 300mAH (Built In)BT Version: 5.1BT Transmission Distance: 12m / 39.4ftWireless Fidelity Transmission Distance: 20m / 65.6ft.Package List:1 xNeckband Headphones1 x Instruction Manual1 x Supply Cord1 x ReceiverNote:Multi device expansion is only available with the original headphones, other headphones are not suitable.