The Shokz OpenSwim Open Ear Wireless Headphones, formerly Xtrainerz, are engineered with Shokz’s signature open-ear design and 7th generation bone conduction technology to ensure bud-free, comfortable listening all day, in or out of the water. Traditional earphones need to be plugged into ears deeply and firmly to make sure ear is sealed especially with intensive body movement. The painful experience and proness to ear infection have greatly hampered the popularity of earphones amongst swimmers. Powered by bone conduction technology, Xtrainerz swimming MP3 headphones are ears-free and eliminate these problems.