High quality material: Made of hardened tool steel, it has good wear resistance, heat resistance and corrosion resistance. The nozzle has an overall hardness of 50 HRC and a surface hardness of 55-60 HRC, giving it a long service life. High temperature resistant: The nozzle can withstand temperatures ranging up to 450 degrees and suitable for high temperature 3D printing, not only for common 1.75mm 3D printer filaments, but also for printing PLA, ABS, carbon fiber filaments and even made of PEEK. Wide compatibility: works with almost all FDM printers and can be mounted on an mk8 heater block. These nozzles are compatible with the mk8 hot ends of the e3d v5 / V6 and Ender 2 3S 3 pro, but also with the Cr - 10 all Metal hot ends, prusa I3, Anet A8, reprap, etc. High precision: The inner wall of the 0.4mm diameter nozzle is smooth and burr-free, with a low viscosity coefficient. What you get: The package comes with 5 steel nozzles 0.4 mm black hardened.