What tools can it hold?

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.