This is a bottom plate and top cover for easily building an RC tank using Makeblock aluminum profiles and tracks.
Roboclaw 2x15 A Controller
Pololu Metal Gear motors with quadrature encoders
Straps (for holding the battery under the bottom plate)
You will also need a 7.4V or 11.1 V LiPo depending on if you want to use 6V or 12V engines.
Here is a small video of my daughter running it for the first time:
Son driving a variant:
Me driving over son's tank:
The version she is driving is a low powered 6V version with a gear ratio of 1:75. It can pretty much traverse anything.