Model:Celebrat-A22 Best working distance: <6m Frequency response: 20Hz-10KHz Drive unit: 10mm Wireless version: V5.0 Battery capacity: Lithium battery 3.7V/140mAh Working frequency: 2402-2480MHz Impedance: 32Ω±15% Play time: About 8 H(70%volume) Sensitivity: 88dB±3dB Transmission distance: 10m Call time: About 7.5 H(90%volume) Input voltage: Micro USB/DC 5V /500mA Charging time: About 2.5 H Standby time: About 350 H