This is one very very rare piece of kit an Xfactory X5 - XX4 conversion kit.
The idea behind this was to take the off-road performance and handling of the Losi XX4 and combine it with the straight line acceleration of the XXX4+.
They stopped making these kits after the original Chassis mold broke so a real piece of history!
Apparently they were an awesome conversion and the cars ran really well:
http://www.oople.com/rc/photos/reviewx5/index.html
