Novak's latest version the SS Pro Racing Series 13.5 Brushless Motor. Similar in power to fast stock racing motors. From Novak's Web Site: Although the SS13.5 brushless motor has received several new upgrades including a Novak sintered rotor. SS13.5 UPGRADES & STANDARD SS PRO MOTOR FEATURES The #3413 SS13.5 received several new upgrades for improved performance. The first upgrade to the SS13.5, and a standard feature of the SS Pro Series, is the Novak ROAR-approved, Nickel-plated Sintered Neodymium rotor. The rotor is the same high-performance rotor that the Velociti 3.5R motor currently features. The rotor is ideal for use with any and all applications and provides many benefits, including: Significantly increased magnetic strength for improved throttle feel Improved, stronger motor braking power Improved performance in higher temperature conditions Improved motor acceleration and power. Higher efficiency Lower current draw Nickel-plated rotor for a long lasting, smooth, clean finish. ROAR approved. The second upgrade to the SS13.5, and a standard feature of the SS Pro Series, is the set of ribbed aluminum end bells. The lightweight aluminum end bells not only reduces the overall weight of the motor, but the ribbed design also acts as a heat sink by efficiently removing excessive heat from the motor. The last upgrade to the SS13.5 is the orange timing ring located on the rear end bell. The color-coded, non-removable, non-replaceable timing ring will be of great assistance to race directors and officials in ensuring the correct motor is used during racing. The timing ring is a visibly easy way to check that racers’ are compliant with race rules. The SS10.5 Pro features a blue timing ring located on the rear end bell. ADDITIONAL SS PRO MOTOR FEATURES The SS Pro brushless motors will be equipped with all of the great standard features found on all Novak motors, including: a convenient Solder Tab System for easy wire replacement; Sensor-Based Technology for excellent starting torque, low-speed drivability, and smooth acceleration; the same Oversized Front Bearing used in Novak’s Velociti-series motors that is more rugged, extra durable, and helps extend motor life; and Thermal Overload Protection (when used with a Novak brushless ESC) that allows pack after pack to be run without fear of damaging the motor, battery, or speed control.