Excluder

The Excluder was a sonic device manufactured by Merr-Sonn Munitions, Inc.. A handheld device, they emitted waves of high frequency sound that warded off many creatures while at the same time being inaudible to Human and many other alien species' hearing. It did affect some species, however, such as Wookiees. The Merr-Sonn Excluder had three settings, capable of creating a disruption field of 10, 20 or 40 meters, respectively.

A small group of Rebels, including Homack, used excluders while on a mission to the planet Hethar. Four sentries heard shredder bats approaching and used the devices to disrupt their senses, before killing the dangerous predators.

Text and facts from the “Excluder” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.