Bluetooth Version: 5.0 JL6973D4 Battery inside earphone: 40mAh without protect PCB Battery inside chargingcase: 320mAh with Protect PCB Speaker: 10mm Impedance: 32ohm Frequency:20-20kHz Sensitivity: 105dB+-3dB Working time: 6-7hours Standby time: 168hours Digital display in charging case injection color: white or black closed box