[Source] The XX-23 homing beacon was an s-thread tracking device produced by Neuro-Saav Technologies and used during the Galactic Civil War. The XX-23 was a small cylinder that broadcast a continuous signal that could be received by HoloNet s-threads. A dedicated computer would then be able to determine when the ship crossed an s-thread and plot its course with this information. It could be attached to the hull of a ship via a molecular bonding agent. It would use a ship's heat and radiation emissions to power itself, making it more difficult to detect than other trackers.