Battery Type: Transmitter: AAA Battery x 4 (sold separately) / For Running: AAA Battery (alkaline or Ni-MH) x 4 (sold separately) [Set Contents] -RC unit built-in half completed chassis (MR-03VE-W-MML mode) -Front car width changing parts (*RM motor case not included) -Pinion gear (6T, 7T, 8T, 9T) -Spare nut -Wheel wrench -Pinion removing tool