Bluetooth connection: Wireless connection, frees you from twisted or kinked cable. Up to 10 meters operation range, no need to worry about the disconnection while you are on a move. Music card support: This headset is like a MP3 player. You can insert the music card in the headset and listen to all the music you want. Audio cable applicable: If the headset runs out of power or you have to connect it to a device with no Bluetooth connection, you can connect them with a 3.5 mm audio cable. This is a very convenient and thoughtful design. High quality: Built in high quality audio coded, giving you excellent voice experience, Ergonomic design make this headsets comfortable for long time wearing. Foldable design makes it easy to carry with.