specifications: Bluetooth Version:BK3.0. Frenquency:2.402-2.480GHz. MAX Power output :3W MIC Sensitivity:-32db . Receive Sensitivity:Better than +82dBm. Range:10meters . Data Transmission:Up to 3Mbps UART Data Transmission Rate:115200bps . Charing Voltage :4.8V -5.2V DC. Working Voltage:3.7V -4.2V DC. Working Current:200MA. Quiescent Current:>1UA. Battery :250MAH. Antenna:Built in Wireless Bluetooth Input;Hands free phone with MIC; TF card function;