Unilateral retractable internet Skype hand-free:1. We self to do 13mm earplug of earpieces, iscomfortableto ears,it inside receiver and microphone, the weight is only 3.2g, is most light in the world.2. Just only 2 seconds when youreceiving the call, pull it lightly and wear on ears, it let your hands freedom.3. The unilateral retractable device (Patent) could solve the trouble of clean cable, it's quickly clean and collect, and convenient to carry with you.