Micro brushless inrunner.
Spec.
Battery: 1 Cell 1S/3.7V
RPM: 11500kv
Max current: 4A
No load current: 3.7V/0.4A
Current capacity: 4A/1sec
Internal resistance: 0.51ohm
Dimensions: 10x15mm
Weight: 5.1g (kv11500) (not including connectors)
Diameter of shaft:1mm
Length of front shaft:5mm
Suited for Mini EDF or micro brushless cars.