This is to mount a Dremel 225-01 Flex Shaft onto a MendelMax 2. It is very sturdy and fits snugly. I used it to mill circuit boards and experiment with other things, and it works wonderfully. I am proud of this one for being so simple and working so well! To Use: 1 - Unmount your hot end/extruder/fan 2 - install this mount on the underside of the hole in the X-Carriage where the hot end was 3 - remove the knurled plastic nut from the Dremel 225 tool end 4 - insert the Dremel 225 into the mount 5 - install and tighten the knurled plastic nut on the Dremel 225. It will tighten enough to hold very securely!