Bypass displacer
From Memory Alpha, the free Star Trek reference.
A bypass displacer is a piece of technology, used by the Cardassians in the 24th century.
Bypass displacers were amongst the components sought by a Starfleet salvage team sent to Empok Nor in 2373. Miles O'Brien listed their necessity as "would be nice". (DS9: "Empok Nor")
