Model:Celebrat-A4 Best working distance:<5m Frequency response:20Hz-10KHz Drive unit:40mm Wireless version:V5.0 Battery capacity:Lithium battery 3.7V/300mAh Working frequency:2402-2480MHz Impedance:32Ω±15% Music time:About 8 H(70%volume) Sensitivity:107dB±3dB Transmission distance:10m Talk time:About 8 H(70%volume) Input voltage:Micro USB/DC 5V /500mA Charging time:About 2 H Standby time:About 90 days