Bluetooth® version: 5.3 Bluetooth protocols: A2DP, AVRCP, HFP, HSP Maximum connection distance: 10 meters Battery capacity: 350 mAh for charging case, 30 mAh for each earpiece Battery voltage: 5V Charging time: 1 hour for charging case, 1 hour for headphones Play time: About 6 hours Impedance: 16 Ohm Sensitivity: 98 dB+/3 dB at 1K Hz Earpiece diameter: 6 mm Frequency response: 20 Hz20 kHz