Chipset: Pixart 1603 Support: A2DP1.3/HFP1.6/HSP1.2/AVRCP1.6 Bluetooth version: 5.0v Speaker size:Φ12mm Impedance: 32Ω ± 15% Frequency range: 20Hz-20kHz Effective range:up to 10 meters Earbud battery capacity: 2*50mAh Bluetooth work time: up to 4.5 hours Standby time: 60 hours Charging case battery capacity:350mAh Earbud charging time:~1 hour Charging case charging time: ~ 2hours Input rating : DC5.0V Sensitivity: 95+/-3dB Work voltage: 3.7V Microphone sensitivity: 43+/-3 Charging port: Type-C USB MOQ per customized color 2000pcs