This will be a tuned motor to be used with Star-Unit Series releases, and may employ Item 55105 or Tamiya R6/AA/UM3 batteries as an electric supply. See below for compatible pinion gears.
Appropriate Chassis
SW-01*1 & T3-01*2 Chassis
*1Compatible pinion gear: Item 54228 (26T only). Utilize with Items 54834, 54857 and 54876.
*2Compatible pinion gears: Things 50354 (16T only) and 50355 (18T just). Utilize with Items 54900 and 54928.
*The official Tamiya R/C Parts Matching List has a great amount of information about chassis suitable for Tamiya Spare and Hop-Up choice parts.