Unilateral retractable hi-stereo earphones: 1. It adapt hi-stereo speaker, could letyou enjoy authentic music, don't tired your ears for long time. 2. We use silica gel earpiece, also let your ears comfortable when listen. 3. Special clip design, usage of hang and grip, it could be upon neck, belt, pocket, and bag; etc. 4. The unilateral retractable device (Patent) could solve the trouble of clean cable, it's quickly clean and collect, and convenient to carry with you.