CNC Stylus - What tools can it hold Home » Knowledge Base » CNC Stylus Knowledge Base » Before You Buy » What tools can it hold? CNC Stylus Knowledge Base Before You Buy What does it do? What is included? What is special about it? What tools can it hold? Will it fit in my CNC machine? Tutorials Cutting vinyl stickers Drawing with a pen or marker CNC Stylus Knowledge Base Before You Buy What does it do? What is included? What is special about it? What tools can it hold? Will it fit in my CNC machine? Tutorials Cutting vinyl stickers Drawing with a pen or marker The ER-25 collet system CNC Stylus uses an ER-25 collet system which means it can accept collets which can hold diameters from 1mm – 16mm.This allows you to insert tools of a wide range of sizes. With the CNC Stylus package, we include a common set of collet sizes to get you started (8 -16mm). Do I have to buy specific pens and cutters from YetiTool? No, you can use any tool you like as long as the diameter is no larger than 16mm.