This drill bit set is perefect for cleaning the nozzles on 3D printers when it gets clogged. There are 5 types of drills included in the pack which consists of 0.2mm 0.3mm, 0.35mm, 0.4mm and 0.5mm sizes which are suitable for nozzles of 0.2mm to 0.5mm. By using these precision drill bits, you will certainly extend the life of your 3D printer nozzle.