Wikipedia
Zyklon-B was a Norwegian black metal band founded in 1995.
The band’s members were Tomas "Samoth" Thormodsæter Haugen ( guitar and bass) and Vegard "Ihsahn" Sverre Tveitan ( keyboard) from Emperor, Kjetil "Frost" Haraldstad ( Drums) from Satyricon and Björn "Aldrahn" Dencker Gjerde ( vocals) from Dødheimsgard. Their lyrics deal mainly with death, apocalypse and warfare. The band recorded only one EP; other versions of the featured songs were featured on split releases with Mayhem and Swordmaster.
The band Zyklon featuring members of Zyklon-B is often thought to be the same band, which is wrong. The name refers to Zyklon B, a gas used in gas chambers during the Holocaust. However, the band states that "Zyklon-B is not related to any political or racial preference".