3D printing pros working with abrasive materials, this Micro Swiss nozzle is exactly what you need! Made from A2 steel that's heat treated to 57-62 RC, this .4mm nozzle is seriously wear-resistant and built to handle tough filaments that would destroy standard brass nozzles. Important note - this ONLY fits Micro Swiss MK10 All Metal Hotends because it has completely different internal dimensions designed to work with their thermal barrier tube. If you're printing with carbon fiber, stainless steel, wood-filled, or any other metal-filled filaments, this nozzle will dramatically extend your equipment life and maintain print quality. Made right here in the USA by Micro Swiss, you're getting that quality craftsmanship and precision that the brand is known for. The hardened steel construction means you won't be replacing nozzles constantly when working with abrasive materials. It's one of those upgrades that pays for itself quickly if you regularly print with specialty filaments. Your all metal hotend setup just got the perfect companion for tackling those challenging materials without worrying about nozzle wear ruining your prints.