4.1 4 poles rotor, high efficiency (>90%), the additional heat-sink is unnecessary in most applications.
4.2 New design with lighter weight but bigger torque.
4.3 Higher power, faster acceleration and higher top speed.
4.4 Top quality materials:
Aluminum shell (case)
High quality magnets
Copper wires of high temperature endurance
Good quality bearings
4.5 Anti-broken rotor with special workmanship.
EZRUN COMBO SC-C4 WaterProof Motore 4274 Lite ESC 120A.