Bluetooth version: V3.0 + EDR (compatible with the version below 3.0); Working frequency range: ISM frequency band (2.4~2.48GHz); Wireless connection range is up to 10 meters; Supports handsfree Headset bluetooth agreement rules; Dual standby you can connect two phones simultaneously; With built-in DSP noise suppression and echo cancellation the voice and sound become clearer and louder; Supports multiple languages: Chinese English Spanish (like turn on/off ready to pair phones connected disconnected incoming callsetc); Also supports TTS function when phones coming; You can answer the private calls with private earphones; Supports A2DP music playing via mobile phone; With FM transmitter you can listen to the music via mobile phone; Well compatibility compatible with all kinds of mobile phones computers MID and other devices with bluetooth; When this device is disconnected with bluetooth for 10 minutes it will turn off automatically; Press "pick up" button to answer phone; Press "FM/SPEAKER" button you can switch mode betwen FM and speaker; FM transmiting status: light is steady on; Press "FM/SPEAKER" for 3 seconds then light flashes once and the frequency is 96.8MHz; When the light flashes twice the frequency is 97.3MHz; Flashes three times the frequency is 97.8MHz; Flashes four times the frequency is 98.3MHz; Flashes five times the frequency is 98.8MHz; Every time you press "FM/SPEAKER" button for 3 seconds it will automatically switch to next frequency; When it is in SPEAKER mode the light doesn't flash.