Lee Jung Hwan (Hangul: 이정환; hanja: 李征桓; born March 20, 1992), better known by his stage name Sandeul, is a South Korean idol and the main vocalist of boy band B1A4. He made a debut on the stage of MBC Show! Music Core on April 23, 2011. He has been part of five Korean mini albums, two Korean studio albums, and two Japanese studio albums.