The pods resembled large cubes with platforms and small activation consoles inside. A pod's machinery was vulnerable to sonic waves but could be repaired quickly with a Sontaran baton.
Small beacons were also used in the campaign. These resembled discs and could be attached to surfaces, allowing the Sontarans to teleport things onboard their ship. (TV: The Sontaran Stratagem / The Poison Sky)
After the invasion was repelled, the pods came into the possession of UNIT who began experimenting with the technology. This led to the creation of Project Indigo, but Jack Harkness claimed it was dangerous because there were no proper coordinates, or stabilisation. (TV: The Stolen Earth)