da Vinci Junior 0.3mm Print Head Upgrade This print head upgrade decreases the print nozzle size from 0.4mm to 0.3mm, increasing the print detail whilst maintaining the fast print speeds enjoyed with the da Vinci Junior range. Attaching this to the da Vinci Junior is very simple via the push/ release mechanism found on the print heads. The smart temperature control found within these heads assures the stable extrusion of filament which delivers perfect layering during printing. The da Vinci Junior print head features a smart detection system which allows self-calibration of the Z-axis. This unique design is perfect for hands-on beginners & makes calibration effortless.