[. . . ] ˎˎBe careful not to catch your fingers when you fold the headphones. Ό‘ËŽIf you install the Smart Key app* from Google PlayTM store, the track and volume adjustment on your smartphone will be enabled with multi-function button. The app may not be available in some countries and/or regions, and may not be used with unsupported smartphone models. [. . . ] Available operations for iPhone Plays/pauses a track of the connected iPhone product with a single press. Starts the “VoiceOver**” feature with a long press (if available). Notes ˎˎIf you connect to an unsupported smartphone, the microphone of this unit may not function, or the volume level may be low. ˎˎThis unit is not guaranteed to operate digital music players. Using the Multi-function button* Press once to answer the call, press again to end; press to play/pause a track. Available operations for iPhone Plays/pauses a track of the connected iPhone product with a single press. Starts the “VoiceOver**” feature with a long press (if available). Notes ˎˎIf you connect to an unsupported smartphone, the microphone of this unit may not function, or the volume level may be low. ˎˎThis unit is not guaranteed to operate digital music players. Using the Multi-function button* Press once to answer the call, press again to end; press to play/pause a track. Available operations for iPhone Plays/pauses a track of the connected iPhone product with a single press. Starts the “VoiceOver**” feature with a long press (if available). Notes ˎˎIf you connect to an unsupported smartphone, the microphone of this unit may not function, or the volume level may be low. ˎˎThis unit is not guaranteed to operate digital music players. Using the Multi-function button* Press once to answer the call, press again to end; press to play/pause a track. Available operations for iPhone Plays/pauses a track of the connected iPhone product with a single press. [. . . ] Avoid using the headphones where they are liable to be struck by people or other objects, such as a ball, etc. Pressing the headphones against your ears may produce a diaphragm click sound. Only the supplied headphone cables and headphone cables for MDR-100AAP (sold separately) can be used with these headphones. [. . . ]