Transition Engine

An archeotech engine that uses technology that far surpasses knowledge of today's scientists to literally teleport ship to a chosen place in space. The science behind this is so incomprehensible that sensible theory that explains its existence is yet to be created.
Transition Engine allows for the instant, FTL teleportation. However, due to energy cost it cannot be used to teleport object for a distance longer than approximately 0,64 ly. This makes it an FTL drive that can only be used like a STL engine. Thus it is generally considered one of them.