Bluetooth smart anti dust bone conduction headphone face Mask Name: Bone conduction Bluetooth mask SKU:HNE-KZ1 Chip: CSR8635 Speaker type: bone conduction 1W dual speakers Battery: 320 mA polymer battery Microphone: -50db Anti-interference microphone Duration: 7 hours Standby time: 15 days Effective range: 15 meters Channel: Stereo Bluetooth version: EDR4.0 Weight: 299g Color: black TFcard: No FM: No Frequency range: 20-20KHz Features: *2 in 1 Function: Earphones + Mask type *Compatible devices with Bluetooth, such as mobile phone. *Perfect sound quality and effect, when you go out to enjoy unfettered music anywhere. *Stereo Bluetooth transmission, strong output power with outstanding sound quality. *Mask type, ultra-fine filter, free breathing, highly resistant to PM2.5/bacteria/dust/suspended particles. *Rechargeable, suitable for both indoor and outdoor exercise. *Bone Conduction,free your ears, less harm to eardrum, more safety, comfortable and health. Earbud design, care your ears. *support play,volume control,previous song,next song,answer/end calls functions.