These high-quality 3D printing nozzles are designed specifically for use with Prusa's latest extruder – Nextruder. Compatible with Prusa's MK4 and XL 3D printers, they feature an all-metal filament guide which means that Nextruder's filament path is entirely metal. This helps improve overall printer reliability and enables speedier nozzle changing. Simplified nozzle changing. Changing a nozzle on your Prusa printer just got much easier! Waste less time changing your nozzles and more time experimenting with different sizes and materials. Easy identification. Each Nozzle has its size engraved into it. Please note: