kV refers to R.P.M./Volt
Its how motors are rated. Does not mean KiloVolts as in electrical terms.
The higher the kV rating the faster the R.P.M of the motor.
The lower the turns, the higher the R.P.M. of the motor.
3.5T 10,500
4.5T 9,000
5.5T 7,400
6.5T 6.400
7.5T 5,800
8.5T 5000
10.5T 4,200
13.5T 3,300
17.5T 2,200
21.5T 1,800