Hallo, first of all congratulstions for your good work with providing a dual extruder for Ultimaker 2. I am unfamiliar with 3D printing but would try a project with Ultimaker 2 dual extrusion. For this I have the following questions: Can both extruder nozzles have different diameters? I would need one nozzle with original diameter 0.4 mm and the other with 0.2 mm. Can this work with the larger nozzle at normal printing speed and the smaller at reduced speed? How can these parameters be selected in Cura? Do you supply different nozzles sizes and what are the costs? Are there any problems known with dual extruder ABS printing? Which retraction parameter should be used for extruder change? Thank you for your help.