ツィクロンB
The single's A-side, "United", was called "one of the first electropop singles" by Jon Savage., while the B-side, "Zyklon B Zombie", has been seen as a parody of punk rock music. "United" featured a minimal drum loop and synthesizer pattern with uncharacteristically positive lyrics, while "Zyklon B Zombie" featured little more than growling, distorted vocals and bass guitar with a frenetic guitar solo. Both tracks were later released in the CD version of "The Second Annual Report".