If you're looking for the perfect balance of power density and efficiency, look no further.  Up to 3400W at 90% efficiency, 93% efficiency peak.  Handmade in the USA.  Only 3 lbs.

• Max Continuous Rating: 3400W (54V @ 63A) @ 90% efficiency
• Speed Constant: 169kV (RPMs/Volt)
• Weight: 3 lbs
• Length: 3 inches
• Diameter: 3.2 inches
• Shaft diameter: 3/8"
• Shaft length: 2"
• Bearings: Twin ball bearings
• Max Efficiency: 93%
• Sensorless controllers only