A Skid Unit is an ATV used in emergencies and rescue missions. They were used by the Shackleton Co-operative in the Phoenix Files series as transport, and they also used them for emergencies.
"A Rescue Mission"Edit
Luke Hunter, along with Matthew Reeve and other former Phoenix Security staff, used a skid unit to break into the Shackleton Building (in the book Doomsday) to rescue their families and take down the shield grid with a missle launcher. Officer Kirke drove the skid through the barb wire fence and through the front doors of the Shackleton Building, although it cost him his life.