Hobbywing 30401254 Xerun AXE540L R2 2100KV-FOC Sensored Brushless Motor

Features
Word's First FOC brushless system for Rock Crawler.  Field-Oriented Control for Super Linearity & High Torque & Extreme Silence.
The chip-type magnetic encoder inside the motor guarantees consistency between three phases’ signals and always outputs the pure and precise signals indicating the rotor position.
"POLARITY PROTECTION".  Yes. it is not a typo.  No more "oops" moment. The chip-type magnetic encoder inside the motor guarantees consistency between three phases’ signals and always outputs the pure and precise signals indicating the rotor position.
The waterproof and dust-proof design (*IP67 standards) allows the AXE brushless power system to be used in all weather & track conditions without any issue of damage caused to the system from water or dust. Damage to the vehicle caused by water, mud, or conditions should be monitored closely when running in muddy, wet, or adverse conditions.
Intelligent torque output & speed closed-loop control for easy control, and consistent motor RPM under all loads.
The motor with 4 poles & 12 magnets, featuring Hobbywing’s “staggered pole” patent has zero cogging effect & torque ripple. It can work smoothly at low speeds. This greatly improves
the manoeuvrability of rock crawlers at low speeds.
The new sensor harness, which features the plug-and-screw design, has a silicone O ring inside. The new design & O ring not only provide a firm connection between motor and ESC but solve the “waterproof” challenge for sensor ports. 
 

Specifications

XERUN AXE 540L  Motor-Specification
540L FOC motor
KV 1400kv 2100kv 2800kv
30401253 30401254 30401255
LiPo 2-3S 2-3S 2-3S
No-load Current (A) 1.7 2.7 3.6
Weight (g) 211g 212g 213g

1/10-1/8th FOC brushless motor (Patented)
Waterproof, 
Motor Diameter: 36.0mm(1.42in)
Length (mm): 57.8mm(2.28in)
Shaft Diameter: 3.175(0.125in)
Pole: 4