Are you asking about the machine that cuts the bias tape or the small hand held bias folder that folds the bias so you can press it?
This:
http://www.sewing.org/scripts/blog/2...rotary-cutter/
Or this:
http://www.sewing.org/scripts/blog/2...rotary-cutter/
I have heard the cutter isn't all that good, but I have never used one. The tape maker keeps the fingers from blisters and works great!