This is the Hobbywing XERUN SCT 3660SD G2 Sensored Brushless Motor. This 4-pole powerhouse is great for heavy-duty short course, truck and monster truck sensored applications.

Note: Because this motor features a 5mm diameter motor shaft, it requires pinion gears with a 5mm bore. 

Features: 

• Innovative 4-pole-8-magnet "staggered pole" rotor (Hobbywing-patented) with low cogging effect and torque pulsation greatly improves control feel around corners.
• Built-in chip for making the motor be easily identified by HOBBYWING ESCs. When pairing it with a HW 1/8th sensored ESC (i.e., XR8 SCT/Plus), the motor can work in the “sensored” mode at all times with gr eat output linearity after the identification. The Turbo timing is allowed to be activated for higher output.
• Magnetic ring mounted on the rotor protects the motor from signal interference and guarantees its super stability in the “sensor ed” mode.
• With the mechanical timing adjustable from 20 degrees to 40 degrees, users are able to have different output power.
• Turbine design implemented by the rotor accelerates the internal air circulation and reduces heat.
• Rebuild-able design (partially rebuild-able) and screw-less motor case for easy routine maintenance effectively prolong the motor life and raise the motor efficiency.
• CNC machined aluminum housing, high purity copper windings, advanced rotor structure, high-quality alloy steel output shaft, high-precision bearings for high durability and smoothness.
• Updated “U” solder tabs at the bottom of the motor for easy soldering and wiring.

Specifications:
kV (no load): 3200
LiPo: 2-3S
Resistance: 0.0065
No-load Current: 3.7A
Motor Diameter: 36mm (1.417in)
Motor Length: 62mm (2.44in)
Shaft Diameter: 5mm (0.197in)
Shaft Length: 17mm (0.669in)
Poles: 4
Weight: 218g (7.69oz)
Applications: 1/10 heavy duty SCT, truck, monster truck