Working voltage: DC 2.2V-5.5VSignal to noise ratio: ≥92dBEffective distance: barrier-free 10MFrequency response range: 20HZ-20KHZSensitivity: 98dBNominal impedance: 32ΩTransmission power: Class 2Headphone battery capacity: 50 mA/pcRechargeable battery capacity: 300 mACharging input: 5V /500mACharging time: about 2 hoursHours of use: 8-10 hours of talking, 5-7 hours of music playingStandby time: 10-15 days