Air Conduction earphoneTouch controlGood Bass soundClear microphone16mm speaker built-in 23ΩBluetooth version: 5.2Support profiles: HSP,HFP,A2DP,AVRCPChipset: Bluetrum 5616BWireless range: up to 10 metersEarbuds Battery: 70mAhPlayback time: 3.5 hrs per chargeSensitivity: -92dB±3dBFrequency Response: 20Hz-20KHzCharging time: 1.5-2 hrsCharging port: Type-c