Ouphone Bluetooth Handsfree Car kit with LCD 009D Bluetooth Specification: Version 1.2 Compliant Bluetooth Profile Support:Headset and Handsfree Profiles Frequency Range: 2.4 GHz Spectrum Working Distance Range: 10 meters(class 2) Dimensions (Main unit):108(L)*57(W)*31(T)mm Weight(Main unit):129g LCD Display:12 digits caller number display 15 bars volume display,battery status icon,blue backlight DSP:Full duplex transmission,noise suppression and echo cancellation. Pairing: Up to 4 mobile phones Charging time: Within 3 hours Talking time:Up to 10 hours Standby time: Up to 200 hours Rechargeabel Battery: Lithium Ion,3.6v,1100mAh installed Battery Protection: Over charge and over discharge protection Input Current:350mA(internal controlled) Input Voltage:DC 5V Speaker Power:2W(max) Speaker Impedance:8ohm Sensitivity of Microphone:-47dB