The standard 0.4 mm stainless steel nozzles can be replaced with optional 0.6 or 0.8 mm ones to implement different purposes. In addition, there are three carbon steel nozzles of 0.4, 0.6, and 0.8 mm to use for printing with CF (carbon fiber) composite materials. With the nozzle and heating block assembled together, it is easy to replace and maintain.