Characteristics and Interoperability Version of Bluetooth: 5.3 Wireless range: 10 meters; driver size: 10 mm Response frequency: 20–20,000 Hz Each earphone battery is 25 mAh. 180mAh is the charging case battery. Sensitivity of the speaker: 102dB + 4dB Impedance of the speaker: 32 ± 15% Ω Sensitivity of the microphone: -38dB ±3dB Time spent charging: about two hours Maximum standby period of 90 days Up to five hours of work at 70% volume Type-C charging plug