Zeal Sports Earphones with XFit System for iPhone 4/3GS/3G, iPod Touch, nano, shuffle, Microphone, Track Control, Volume Control, Sweat Resistant (Discontinued by Manufacturer) Innovative XFit system keeps earphones comfortably in place even during rigorous activities Our premier audio delivers throaty vocals, rousing guitar riffs and tight bass Sleek InLine control includes: volume control, function button, microphone and Voice control 4 sizes of ECO (Ear Canal Opening) rings work to fit individual ears 2 Pairs of swappable Personalizers included.