LG Stereo Headset HandsFree Headphones plus Adapter OEM (SGEY0003602) Grey Silver 2.5mm Jack for LG VX-5400 Verizon Cell Phone Mutes the music, and operates in mono sound during a call Music resumes in stereo when call is ended Noise-reducing microphone Designed to fit most 2.5mm/3.5 mm universal stereo cell phone models that have stereo output built-in