Make the covert communication possible when it is inconvenient to expose earpieces., Support phone call, FM radio, MP3 player, etc, Compatible with Apple iPhones, Android phones, tablets, Kindle, e-Readers, and any portable devices with a standard 3.5 mm jack. (Apple iPhones needs lightning to audio adaptor),Microphone with 1-Button for clear calls and smartphone control, Note: To avoid possible noise interference when using this device, Keep away from electrical equipment including personal computer consoles, speakers, televisions, refrigerators, etc.