This motor from Brother Hobby was specifically designed for light weight 4inch and 5inch machines. The "returner" series of motors are know for high quality, HIGH output power, and light weight. These motors are a perfect match for the SuperLight 4R racer. 

Specifications

• Configuration: 12N14P
• No.of Cells(Lipo): 3-4S 
• Rotor: N52H arc magnets 
• Wire AWG: 20AWG 
• Shaft: Titanium Alloy hollow shaft 
• Stator: 0.15mm Kawasaki silicon steel
• Bearings: NMB 6*3*2.5mm
• Base casing: Al 7075
• Bell cap: Al 7075
• Weight:21g (with 16cm wire and nut)
• Weight 19g (with short wires and nut)
• Mounting: M3 screws on 12mm circle (Mounting the motor)

Includes

• 1x Returner R4 1806-2850kv Brushless Motor 
• 4x Hex head Screws
• 1x Nylon Prop Nuts