This is Micro Swiss All Metal Hotend kit for Zortrax M200/M300.

This upgrade includes a modified thermal barrier tube and modified nozzle with modified cooling block. Thermal barrier tube is made from 2 different materials. The lower thermal break is made from stainless steel, the colder upper part is made from aluminum. Stainless steel was used for thermal break because it offers low thermal conductivity, and aluminum was used for the upper portion (cold end) because it has much better thermal conductivity, to carry away any heat from the filament into the cooling block. 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. On original extruders that limitation happens around 60 mm/s, depending on nozzle size. All metal hotend solves this problem, plastic is surrounded by thermally conductive nozzle throughout its length.

Kit includes

.4mm Brass Plated Wear Resistant Nozzle Thermal Tube Slotted Cooling Block Custom screw Allen Wrench

Instructions: https://www.youtube.com/watch?v=reIEyph1aLg