Item No NVK-3621 4 SPEC CLASSES IN 1 MOTOR Novak's Ballistic Spec Brushless Motors 10.5T - 21.5T (#3610 - #3621) are completely rebuildable, right down to the hardware. In fact, only one motor is necessary to compete in all spec class races. Simply pick your class of choice, and install the necessary color-coded, hand-wound stator. Each stator includes a factory-installed insert that easily identifies the number of motor winds. Each Ballistic Spec motor is identified by a color-coded insert affixed to the stator, located below the heavy-duty solder tabs. To complete the racing package, this next-generation spec motor series contains an easy-to-adjust timing assemblythat alters the RPM range and retains previous user settings, allowing for strategic and smart spec racing. Additionally, these sleek motors are ROAR/IFMAR approved, boast aremovable shielded sensor harness, and contain a 12.3mm nickel-plated sintered Neodymium rotor for maximum motor acceleration, braking power and performance in high-temperature conditions. A shielded sensor harness is included with each Ballistic Motor. For replacements, click here. SPEED CONTROL COMPATIBILITY All four Ballistic Spec motors are compatible with Novak's GTB Programmable Racing Brushless/Brush ESC (#1710/#1711), the SLYDR Brushless ESC (#1712), the Havoc 3S Brushless/Brush ESC (#1733) and other racing brushless sensored speed controls. Combined, the Ballistic motors and Novak's programmable speed controls create high-performance systems for world-class spec racing. THE NOVAK STANDARD Like all Novak brushless motors, the Ballistic Spec Brushless Motors are designed, tested and built at the Novak facility in Irvine, Calif. Each motor stator is hand-wound for maximum copper fill and individually tested under Novak's strict parameters, including measuring the resistance of each coil to ensure the correct number of turns. The motors are also tuned to the same factory timing, run under a simulated load, dyno tested, and electronically weighed to ensure the best product is sent to customers. Exploded view of Ballistic Brushless Motor BALLISTIC SPEC BRUSHLESS MOTOR FEATURES Sensor-based for excellent torque and low-speed driveability Oversized front bearing [1/2" x 3/16" (12.7 x 4.8mm)] for increased load handling and bearing life Rebuildable design with removable shielded sensor harness, rotor, sensor assembly, wound stator, bearing cap, hardware, sleeve and both end bells Nickel-plated, 12.3mm sintered Neodymium rotor with a 0.125" pinion shaft that accepts all existing pinion gears Meets RoHS compliance and includes 120-Day Warranty Designed, hand wound and dyno tested by Novak in Irvine, Calif., using globally sourced components BALLISTIC SPEC BRUSHLESS MOTOR SPECS Ballistic Motors 10.5T 13.5T 17.5T 21.5T Part Number #3610 #3613 #3617 #3621 Color-Coded Stator Blue Orange Yellow Green KV (unloaded) 4,200 RPM/Volt 3,300 RPM/VOLT 2,200RPM/VOLT 1,800RPM/VOLT Watts 235 195 130 85 Maximum RPM 50,000 50,000 50,000 50,000 Motor Size 2.07" x 1.41" (52.6 x 35.8mm) 2.07" x 1.41" (52.6 x 35.8mm) 2.07" x 1.41" (52.6 x 35.8mm) 2.07" x 1.41" (52.6 x 35.8mm) Motor Weight 6.6oz. (187.0g) 6.6oz. (187.0g) 6.6oz. (187.0g) 6.6oz. (187.0g) Compatible Novak Speed Controls GTBs, SLYDR,Havocs GTBs, SLYDR, Havocs GTBs, SLYDR, Havocs GTBs, SLYDR, Havocs   REPLACEMENT / OPTIONAL PARTS #5351-#5353 Brushless Shielded Sensor Harnesses - 9", 6" & 4"  (replacement/optional) #5416-#5418 Brushless Motor Cooling Kit (optional) #5508 14G Brushless Motor & Battery Wire Set (replacement) #5647/#5651 Cooling Fan 25x25x10mm (replacement) #5731 3.5mm Low-Loss Power Connector - 5 pairs (optional) #5940 Ballistic Front End Bell and Bearings - 1/8" (replacement) #5941 Ballistic Sintered Rotor -- 12.3mm (replacement) #S5420-#S5424 Brushless Motor Sleeves (replacement/optional) #S5932 Ballistic Motor Hardware Kit (replacement) #S5942 Ballistic Timing/Sensor Assembly (replacement) #S5943 Ballistic Back End Bell (replacement) #S5944 Ballistic Bearing Cap with Rear Bearing (replacement) #S6603-#S6608 Ballistic Wound Stators -- 3.5T-8.5T (optional for ROAR Modified racing) #S6610-#S6621 Ballistic Wound Stators -- 10.5T-21.5T(replacement/optional)