If the spindle/router diameter is not listed you may place the order selecting (CUSTOM spindle/router dia.) and send your spindle/router diameter requirements via message. >>>>>NOTE: The price listed covers any size up to 90mm only. For sizes over 90mm please send message requesting a quote.............. This dust boot system is specifically designed for CNC machines equipped with extended collets or for those utilizing extended end mills. Constructed from a 1/2" 3D top plate, the system features a magnetic removable base holding a transparent, flexible screen, providing clear visibility of your cutting or engraving tool in action. The magnetic base can be effortlessly removed, allowing full access for tool installation. Design to fit a the spindle/router size selected and will accept a 4 inch vacuun port