In addition to the double-shaft Torque Tuned Motor PRO, we are introducing two more varieties of double-shaft motor for use with the new Mini 4WD PRO series racers, greatly increasing customization options to give you the edge in official racing events. The REV-Tuned Motor, a high revolution motor capable of excellent top speeds is perfect for use on circuits featuring lots of straightaways. The Atomic-Tuned Motor PRO is a high efficiency motor that features a good balance of speed and torque, which is excellent for running on technical circuits. Both motors feature shaft ends with press fit brass pinion gears for efficient power transmission, and to allow easy use with Mini 4WD PRO Finished Models. *Compatible chassis: Mini 4WD PRO series chassis (NOT compatible with Dangun or non- PRO series racers) Voltage(V) - 2.4-3.0 Torque (nM-m) - 1.0-1.3 RPM(r/min) - 14300-17400 Current (A) - 1.6-2.0