Whether you’re mixing a recording or monitoring a bass line, you want earphones that deliver high-definition bass and super-transparent highs across an ultra-wide dynamic range. SD251-BT in-ear monitors fulfill your need to compose your own tunes in peace, no matter where you are – at a price that is very kind to every budget! 3 sets of ultra-soft earplugs provide perfect fitment for all ears with lasting comfort. When fully charged, SD251-BT provides up to 7 hours of music playback. They come with high-quality USB charging cable for quick charge on the go. A low battery voice prompt is also built in for convenience.UK/EU Power supply included: NoBattery Life: 7 hBattery Operation: YesBattery Type: IntegratedColour: BlackCompatible with: AndroidCompatible with: macOSCompatible with: PCControls: On/OffControls: Mute/Unmute Mic & Push to Talk ButtonControls: VolumeControls: NextControls: PreviousMade in: ChinaFrequency Range: 20 Hz - 20 kHzOperating Range: 10 mPackage Contents: USB CablePackage Contents: HeadphonesPackage Contents: Cleaning ClothPackage Contents: Padded Zip PouchPower Supply: USBPower Supply: BatteryType: In-EarMicrophone: Yes