Shure E4c Sound Isolating Earphones Upgrade your iPod or other MP3 earphones to professional sound quality E4c model offers enhanced bass and smoother frequency response overall Instead of bulky headphones, E4c wearers get form-fitting earpieces that stay securely inside the ear without uncomfortable headbands Sound isolation prevents outside noise from interfering with the music, and creates a quiet space for exceptional audio clarity Compatible for use with 1/8 inch (3.5 mm) audio output ports