This is an all metal hotend upgrade kit for Flashforge Finder and Flashforge Guider 2. All metal hotend will let you print at much higher temperature than possible with original PTFE lined one. Another benefit of an all metal hotend design is more consistent melt chamber control. During slow extrusion rate, in PTFE lined hotend, transition zone from solid to molten plastic tends to creep upward creating more stringy prints. With all metal design a transition zone is always constant, being located right at the heat break. With fast extrusion rate, PTFE tube doesn't have enough thermal conductivity to properly melt all the plastic coming out. All metal hotend solves this problem, plastic is surrounded by thermally conductive nozzle throughout its length.