The NTS Tightening Fixture mounts to the side of your tool cart or bench. It is a fast way to secure tool holders for changing cutting tools, collets, and pull studs too. It works with: CAT, BT, ISO and HSK tool holders. Users can place the tool holder in the NTS Fixture and tighten the locking screw knob to engage the drive slot or wrench flats and secure the tool holder.