The new 0.8 mm Ultimaker 3 Print Cores enable you to print faster than before. Ultimaker Print Cores are compatible with the Ultimaker 3, Ultimaker 3 Extended, and Ultimaker S5 3D printers. The Print Core AA aka the Build Core is used for fabrication of the actual object, whereas the Print Core BB aka the Support Core is used for creating dissolvable supports. Maximize your uptime with new, swappable Ultimaker Print Cores.