Graviton emitter
From Memory Alpha, the free Star Trek reference
A graviton emitter was a device that emitted gravitons. There were several sizes of emitters, some the size of small starships others that were handheld.
Graviton emitters were standard equipment aboard Federation starships like the USS Enterprise-D. They could be calibrated to emit different kinds of graviton beams including full spectrum pulse compression. Geordi La Forge used the graviton emitters to stop solanogen-based lifeforms from entering the universe through a spatial rupture. (TNG: "Schisms")
Deep Space 9 had graviton emitters on its Habitat ring. In mid-2373, they were used to fire a phase-conjugate graviton beam at the Bajoran wormhole. The emitters were sabotaged by the Changeling impersonating Doctor Julian Bashir. (DS9: "In Purgatory's Shadow", "By Inferno's Light")
Several weeks later, a customer at Quark's used a handheld graviton emitter to manipulate the Dabo table to help his friend win. (DS9: "A Simple Investigation")
