Roger showing his transmission pack to N-3RO
A transmission pack was a piece of equipment utilized by Roger, the B1-series battle droid that had been modified. Following the events of the Battle of Hoth, Roger served the Freemakers. During a visit to Tatooine, Naare, a Sith operative, secretly affixed a tracking device to the droid's transmission pack. As a result, she was able to locate the Freemakers and make off with their Kyber Saber crystals. After the Freemakers made their escape from Naboo, they realized that Naare had been tailing them by using Roger's transmission pack.
They wasted no time in getting rid of it. At a later point, Roger reattached it to prevent the rebellious droid N-3RO and his fellow mutineers from killing the Freemakers and Jek-14. This action got the attention of Naare and her new comrade, Graballa. Rowan Freemaker then used the transmission to challenge Naare to a race to Hoth, which was the location of the final kyber crystal.