"Metal Box" was originally released as three untitled 45-rpm 12-inch (30-cm) records packaged in a metal box resembling a film canister with an embossed PiL logo on the lid (it was later reissued in more conventional packaging as a double LP set, "Second Edition"), and features the band's trademark hypnotic dub reggae bass lines, glassy, arpeggiated guitar, and bleak, paranoid, stream of consciousness vocals. "Metal Box" is starker than "First Issue", more spread out and uncompromising, and scattered with bits of ambient synthesiser. The design for "Metal Box" was the brainchild of Dennis Morris.