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 calls,etc); 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.