An ingestible translator is a capsule-like object that enables the user to speak and understand any language by attaching to the user's larynx via neural interface after swallowing it.
When Rip Hunter's team discovered that Vandal Savage had backed Valentina Vostok's research and that the Soviet Union would possibly gain the upper-hand during the Cold War depending of the outcome of this project, Ray Palmer proposed to approach the Soviet scientist and learn what she knew. Rip Hunter provided the ingestible translators for this plan to work. Rip assigned Leonard Snart as Palmer's wingman; after ingesting the translator, they were both able to speak and understand Russian, as Gideon demonstrated by manually changing Ray's language temporarily to Russian and back again. Later, Martin Stein also took one of the capsules in order to investigate Luskavic Labs.
After Nate Heywood accidentally travelled to Feudal Japan, Ray Palmer swallowed an ingestible translator in order to speak Japanese to a group of Samurai, indicating that the translator he swallowed previously was not permanent.