This is a Z scale EMD TR4 A-Unit (Cow Unit) based on the SW9 locomotive. This model comes with a shell and frame. To power this model, use the motor, trucks and circuit board from a Rokuhan Shorty Motor Chassis B (sold seperatly). Brass is available now but other materials will be available soon.
You will also need the following:
Trucks & fuel tanks sold here
Handrails and decals sold here
Rokuhan Shorty Chassis B (available wherever Z scale model trains are sold).
Instructions to assemble it are here; http://www.thezmaker.com/