Yes it is compressed air. And it also sprays a little bit of oil over the work piece and on the mill. You don't really see it but i love it.
The work piece keeps cool and the mill lubricated. The video is about 12x faster than original. I am gone update the mill motor for higher rpm.
So i also can increase milling speeds. i really need that enclosure then i can go full speed!! And if any one needs something milled don't hesitate to ask!
stef