1. Transmission distance and Bluetooth version independent, depending on the Bluetooth technology Powerclass.

Most mobile phones and mobile devices use POWERCLASS2, the standard transmission distance of 10 meters, while the upgraded POWERCLASS1 is to increase the transmission distance to 100 meters.

2. bluetooth headset radiation is very large normal Bluetooth headset the general radiation is only between a few one-tenth to thousands of of the mobile phone. 

3. Phone and listen to music bluetooth headset is the same kind of hfp mainly for the hands-free hand-based Bluetooth headset, it actually has more headset control functions, such as redial, call retention and reject calls and other functions. HFP is a more emphasis on the headset function of the Bluetooth headset, HFP bluetooth headset is relatively more attention to the function of headphones, mainly used to listen to music.