Professor Motor "Low Voltage Scale Racer PRO" Model Electronic Slot Racing Controller -  Recommended Operating Voltage Range : 10 to 15 volts - POSITIVE polarity - Includes 25 Ohm variable brakes, variable sensitivity (single knob adjust), internal aluminum heat sink, heavy 13 gage silicone leads & solid copper alligator clips w/boots - New "Platinum Series" transistor based technology - Recommended Applications : 1/32 & HO home, club and commercial racing through JK Falcon & 16D Motors