A stealth device, alternatively referred to as a cloaking device, represented a technological advancement that could make a starship imperceptible.
By disrupting the electronic signature normally put out by its various systems and sensors, a cloaking device made an object utterly invisible to virtually all detection methods. However, the magnetic signature of the object could still be used to track it. Cloaking devices, a type of experimental starship technology, let ships get past enemy ships and fleets without being noticed, making them practically undetectable by standard scanners. However, stealth technology was rendered inoperable and vulnerable to detection by an interdiction field. Hibridium or stygium crystals were both capable of powering cloaking devices.
For many generations, Chiss Defense Force scientists had dreamed of creating a working cloaking device.
Darth Maul's ship, the Scimitar, was equipped with a cloaking device, which he employed to launch a surprise assault on pirates who were attacking Trade Federation forces above Kellux. The pirates, caught off guard, were eliminated by proton torpedoes and mines launched by the Scimitar.
Admiral Trench fought cruisers with cloaking devices before the Clone Wars. He did, however, manage to strike them with tracking torpedoes whether they were cloaked or not.
During the Clone Wars, Republic engineers used cutting-edge starship technology to build the stealth ship, a heavily armed ship outfitted with a cloaking device. Jedi General Anakin Skywalker utilized the vehicle to deliver supplies to Senator Bail Organa's base on Christophsis. Skywalker also used it to strike Trench's command ship, the Invincible, though. Despite the failure of his initial strike, Skywalker turned Trench's tracking torpedoes against him, directing the missiles back at the Invincible, destroying the bridge, seriously wounding Trench, and briefly breaking the blockade.
Later in the conflict, Cad Bane, a bounty hunter, received a modified Rogue-class Porax-38 starfighter with a cloaking device as payment from his Sith Lord client, Darth Sidious. Sidious himself used the cloaking device on the Scimitar, Darth Maul's previous ship, to get to Dathomir undetected. He and General Grievous engaged Maul and his Shadow Collective in battle there, in a last confrontation with Mother Talzin. Asajj Ventress made use of the cloaking device on the Lancer-class pursuit craft Banshee to transport Anakin Skywalker and Obi-Wan Kenobi aboard a Providence-class Dreadnought in order to rescue Quinlan Vos.
The Carrion Spike, Grand Moff Wilhuff Tarkin's own corvette, was equipped with a cloaking device modeled after the stealth ship employed at Christophsis and powered by stygium crystals. During the Galactic Civil War, it was extremely unusual for smaller ships, such as the Millennium Falcon, to have cloaking devices. During battles against the Rebel Alliance, cloaking devices were utilized by shadow troopers.