This dust boot fits on a Onefinity Elite CNC machine with a 80 mm spindle. It is designed to sit off to the right side and allow the optional laser module to work without having to be removed. You should set up a soft limit on the Z-axis to prevent collision to the right rail. Its a tight fit and has two 8mm threaded bolt holes to aid in securing it. Both 6mmx3mm and 10mmx5mm magnets are used to allow for quick and aligned “snapping” together of the lower units. An extension is included if using longer bits. Just make sure the magnets are oriented the correct way before inserting. Happy CNC wood making.