lower speed than most bench grinders. Most bench grinders operated about 3,600 RPM but my fastest buffers are about half that, 1725 RPM. The one that I use for buffing with carnauba wax is geared down to about 700 RPM. The fast buffers really generate a lot of friction even with carnauba wax and it can heat things up very quickly if you weren't careful.
Buffers are also a very dangerous because they can whip something out of your hands and across the room. Most knife makers agree the most dangerous piece of equipment in their shops are their buffers.
Once you have a buffer throw a knife back at you you will soon become very cautious when you use them. I know.
Sorry for the double