This is a new technology Brushless motor, designed to work with Hornet, Piccolo  and other possible 350-370 series helicopters
The motor comes Integrated with Cooling Fins for best performance

If using Airplanes, Those motors can be used Park flyers under 15oz..
A high performance upgrade for ant "350-370" powered model.

Specifications:
Motor Type:B20-S ( 100 watt ,speed 280-300 replacement)
Speed: 4091 K v
Idle Current: 0.5
Resistance:0.108
Length : 34 mm
Diameter: 20mm(25 with Fins)
Shaft Size 2.3mm
Weight : 49 gr