Multi Material Upgrade 2S (MMU2S) is the third generation of the unique multi-material addon, which enables the Original Prusa i3 MK2.5S/MK3S 3D printer to print with up to 5 filaments at the same time, with an easier calibration process, new filament sensor and a standalone filament buffer, the MMU2S is more reliable than ever before. MMU2S comes with a redesigned body and a new filament loading mechanism. Instead of the previous Bowden system, the new unit uses a direct-drive feed and a single PTFE tube to lead the selected filament to the extruder. The motorized selector head has a F.I.N.D.A filament sensor and a built-in blade, which prevents filament jamming.