Antimatter inducer

Antimatter inducers are essential warp drive components that are associated with a starships fuel consumption. In theory, the more efficient the inducers are, the less fuel is consumed during a journey. (ENT episode: "Twilight").

When Admiral James T. Kirk and the former command crew of the USS Enterprise hijacked a Klingon Bird-of-Prey in 2285, Montgomery Scott had difficulty locating the vessels inducers. However, with the assistance of Pavel Chekov they were able to locate the inducers and fly the vessel. (TOS movie: Star Trek III: The Search for Spock).

When the Enterprise staff then re-boarded the Bird-of-Prey, following the completion of Spock's fal-tor-pan, Scotty remarked that the "damned" inducers were still where he left them. (TOS comic: The Mirror Universe Saga: "...Promises to Keep").