Medusa 70mm and 80mm motors?

[bruce750i]

"*Based on adequate air flow around motor, i.e., open air stream behind propeller
**Max I can be present for 30 seconds
All Medusa Research motors are rated for 60,000 RPM operation
For the best efficiency, your ESC should be setup with 8º to 15º advance, and a switching rate of 10 to 20kHz.
The above motors have 4 poles."

Right from their V2 page.