This technology is capable of making a vessel or other object invisible to observation and most sensors. The cloaking system was first developed by the Romulan Star Empire, and was then acquired by the Klingon Empire. The technology has been utilized by Starfleet. However these uses are strictly limited due to the The Treaty of Algeron signed in 2311. It requires a considerable amount of power to function effectively. While under cloak, shields and weapons cannot be used.