Product : Color: Black Connection: Bluetooth 5.0 Effective distance: about 10m Audio headset sound quality: strong bass Headphone material: ABS + PC Product material: plastic Speaker unit: 27mm speaker impedance is 32 ohms Headphone battery: 450mAh Music playback time: about 10 hours Headphone charging time: about 1-2 hours Headphone diameter: 4.1cm Headphone cable length: 22.3cm Battery capacity: 450mAh Speaker equipment: internal magnetic speaker Product features: Bluetooth 5.0, hands-free calling, true stereo, TF card playback, FM radio Package includes: 1 * USB charging cable 1 * Headphone Comfortable experience: The bone conduction headphones Bluetooth V5.0 are small and portable and do not need to be put in your ear. It is very safe to release your ears and hear the sounds around you in this way. Excellent technology: Allow ears to be open to ambient noise, suitable for runners and bikers, excellent stability when exercising. Bluetooth V5.0 technology enables fast transmission and smooth connection. The headsets are compatible with most Android / IOS / Windows devices. Wildly compatible and excellent battery life: Connectivity with excellent sound quality and clarity up to 10 meters from the phone, built-in microphone, clear calls. After only 1-2 hours of charging, you get a 5-hour battery (working time varies depending on volume and audio content) Other functions: The wireless bone conduction headphones ensure hands-free calling / answering and listening to music (HD stereo sound quality, comfortable, ear-free, sweat-proof)