Horizontal flywheels are a type of heavy rotating weapon, and among the most famous and destructive weapons in Robot Wars. The pioneer - and most successful example - was Hypno-Disc in Series 3, who inspired numerous derivatives and imitations in later series. Despite this, apart from Hypno-Disc, only 13 Black, Destructive Criticism, Botwork, and to a lesser degree; Disc-O-Inferno and Supernova, also achieved considerable success with this weapon type, with other competitors suffering from inexperience.