This is a new technology Brushless motor, designed to work with Mid size Electric Helicopters like 600 size
The motor comes Without Cooling Fins. If special High power application needed, please Purchase a Heat Sink for best performance
This Motor is German quality without paying for German Made

B50S used in helicopters like Quick, Logo, and others
Some of cars and Airplanes using those motors as well.

Specifications:
Motor Type:B50
Speed: 3900 K v
Idle Current: 3
Resistance:0.12
Length : 58 mm
Diameter: 28 mm
Shaft Size 3.17
Weight : 85 g