The circle on each bud is a button you can use to navigate music and calls. Here's how to use it.
Play/Pause = Quick Press
Next Song = Double press (Note: This only works when music is playing.)
Answer Call = Quick Press
End Call = Double Press
Cancel Call =Press and hold for two seconds
Siri or Voice Command = Double Press (Note: This only works when music is not playing.)
Switch EQ = Press and hold for 3-5 seconds. A voice will indicate the new setting. (Note: This only works when music is playing.)
Third Party Calls
End current call and answer new call = Quick press
Reject new call = Press for one second
Answer new call but hold current call = Double press
Switch between calls = Double press. A tone will sound.