Imperial Sienar Sentinels, or ISS for short, were picket ships used by the Imperial Remnant's starfleet while under the command of Head of State Jagged Fel. These ISS ships were responsible for maintaining the Home Fleet's blockade around the planet Exodo II and the remnants of the moon [Boreleo]; however, in 44 ABY, Abeloth managed to evade the blockade and establish contact with Admiral Natasi Daala, who was a rival Imperial. The starship type was named after its manufacturer, Sienar Fleet Systems.