The Virtual Control Device was a pair of devices conceived by Jadzia Dax that was composed of a master and slave unit. Each device was worn by an individual and allowed the individual wearing the master unit to physically control the movements of the individual wearing the slave unit from a remote location. The master unit had the same point-of-view as the slave unit, allowing accurate control. However, control was limited to the physical limits and stamina of the individual wearing the slave unit. The device used an optronic relay.
In 2373, Quark and Worf used such a device. Worf was helping Quark court Grilka, but as often happens in Klingon culture, Quark was challenged to a battle to the death by Grilka's guard, Thopok. Knowing Quark could not defeat Thopok, Worf agreed to help Quark fight by controlling his movements in battle using the virtual control device. Quark commented that it made him feel "like a puppet." (DS9: "Looking for par'Mach in All the Wrong Places")