A masking transponder served as a tool for duplicating the identifying signals of starships, and was produced by the Corellian Engineering Corporation; this could either hide a starship's true signal or create a false one to distract from the true signal.
In the year 4 BBY, the smuggler Lando Calrissian possessed a collection of masking transponders, stored on his farm located on the planet Lothal. Calrissian bartered at a minimum of four of these transponders to the Spectres, receiving in return three Imperial 49-v99 Deflector shield generators. These transponders then aided in concealing the rebels' departure from Lothal.