This is Acuvance (KEYENCE) Luxon Agile Sensor Controlled Brushless Sensored Motor.
 
Feature:
 
For: 1/10 RC
Material: Aluminum
Color: Black
Larger bearings
Fan on Rotor
Shorter Case Length
 
Specification:
 
INPUT VOLTAGE (V) ※ 1 : 4.8 to 11.1
KV (RPM / V): 3,950
POWER (W) ※ 2: 320
EFFICIENCY (PASENTO) ※ 2: 92
ROTOR TYPE: Sintered φ 12.3 mm (neodymium magnet)
COIL WINDING METHOD: Star winding