It disrupts the process in the Yggdrasil Drive, the engine of Knightmare Frames. This renders them inoperable. However, Knigthmares can be upgraded to shield against them. Lancelot Conquesta is only slowed down by them, not shut down unlike the original Lancelot. Some of the more later mass produced Knightmare frames like the Vincent are not affected either but 5th Generation and below are.