Kim Yoon-sung, known professionally as Gaeko is a South Korean rapper. He and Choiza comprise the hip hop duo Dynamic Duo, which rose to fame upon the release of their debut album Taxi Driver in 2004. In 2015, he released his first solo album, Redingray.

Choi Jae-ho, known professionally as Choiza (Korean: 최자), is a South Korean hip hop recording artist. He and Gaeko comprise the hip hop duo Dynamic Duo, which rose to fame upon the release of their debut album Taxi Driver in 2004. In 2006, he co-founded the South Korean record label Amoeba Culture. He was previously a member of the hip hop trio CB Mass.