Wraith data storage device
From The Stargate Omnipedia
Portable unit designed to hold a variety of Wraith information including sensitive data regarding the hive ship it originally came from, as well as the size of the fleets and locations of the hive ships in the Pegasus Galaxy. Information is encrypted but can be decoded with ciphers.
KEY EPISODES
Underground - After returning the data storage device, stolen in the joint expedition/Genii strike mission, to Atlantis, Dr. Grodin announces that there at least 20 (and possibly 60) hive ships in the galaxy.
The Lost Boys - Jace uses a data storage device to locate the hyperspace "pit stops" of a hive ship in the hopes of infiltrating it.