These high quality 3D printing nozzles are specifically designed for use with Prusa's latest extruder - Nextruder. Compatible with Prusas MK4 and XL 3D printers, they feature an all-metal filament guide, meaning Nextruder's filament path is entirely metal. his simplifies and speeds up changing nozzles compared to before. E3D ObXidian nozzles are particularly suitable for printing abrasive filaments.