AURIA Zeal Performance Sports Earphones for iPhone 4/3GS/3G and iPods with Volume control, Track control, MIC and XFit System Innovative XFit system keeps earphones comfortably in place even during rigorous activities Hear ambient sounds while listening to music Move up to Zeal's nano-technology based speakers for exceptional clarity and low distortion Sleek InLine control includes: Volume control, Track control, and Microphone 4 sizes of ECO (Ear Canal Opening) rings work to fit individual ears