- "Never again will the Rebels leave you behind, looking flat-footed and foolish. The Immobilizer will see to that."
- — Unnamed Sienar Official
Because of its triangular shape, the Immobilizer 418 Interdictor Cruiser is often mistakenly identified as a Star Destroyer. In fact Sienar used the hull design from their Vindicator Heavy Cruiser as a basis for the Immobilizer precisely for that reason.
Immobilizers are specialized ships equipped with four gravity well generators that simulate large planet-sized masses, the purpose of which is to draw craft out of hyperspace or prevent ships from engaging their hyperdrive and fleeing a battle.
This unique technology is particularly useful for trapping and catching pirates and smugglers, and for holding a smaller enemy fleet in space so it cannot avoid destruction at the hands of an Imperial fleet. The gravity well generators are housed in four globe-shaped protrusions.
Creating Immobilizers is financially tedious, so the interdictors are not found accompanying every Imperial fleet. Typically an Immobilizer will be employed patrolling known smuggling routes to catch smugglers and maintain peace and order in a sector. They are usually never seen without support ships.
At first the Immobilizer was equipped only with twenty quad laser cannons, but Imperial technicians were able to find room and power to add an additional four turbolaser batteries and two ion cannons to give the ship a bit more of a bite in battle. Along with two squadrons of TIE series fighters, the Immobilizer is very capable of defending itself from enemy fighters and small cruisers.