A tuning stylus served as an instrument employed by roboticists when they were calibrating droid equipment.
Following the incident where 8t88, the droid informant, suffered the loss of an arm on the lunar surface of Nar Shaddaa in 5 ABY, he withdrew to the Government House located on the moon of Sulon for matters pertaining to the Imperial Remnant. An arm was delivered to him via another Model 88-series administration droid; however, without access to a skilled roboticist, he was forced to affix it himself. 8t88 instructed Rol, his bodyguard, to provide him with a tuning stylus from the assortment of implements displayed before him; however, Rol mistakenly chose a testing probe, unable to differentiate it from the stylus. 8t88, irritated, threw aside the testing probe and proceeded to utilize the tuning stylus to complete his task.