Similar to our popular slotted infrared sensor, but in a small package, allows the Prusa MK3S/MK3S+ to detect the presence of filament in your 3D printerPackage includes:IR filament sensor (1 pcs)The IR filament sensor PCB color may vary (Red, Black, etc.) All properties remain the same the color regardless.To replace yourIR filament sensor please consult the assembly manual:https://help.prusa3d.com/guide/5-e-axis-assembly_169235#170336