[Compatible 3D Printers]: This 2pcs extruder hotend replacement kits are only compatible with for S1/ S1 Combo FDM 3d printers, not for other 3d printer models. Please confirm your 3d printer model before ordering. [Easy Installation]: Compact form factor, the heater block, heatbreak, 0.4mm and 0.6mm hardened steel nozzles come with modular design, eliminating the need for wiring and stripping work. Therefore, this assembled printhead hotend is very easy to install on S1/ S1 Combo 3D printers. [High Quality 3D Printer Accessories]: Includes 2 packs assembled hotend kits, 0.2mm hardened steel nozzle and 0.8mm hardened steel nozzle: for smoother printing and better 3D printed models. [Support High Speed Printing]: Semi-assembled hotend with all-metal throat design makes the print head heated evenly and the filament flows smoothly in the throat nozzle to support high speed printing. And produced by a rigorous design and testing team, no leakage and clogging, you can easily start your 3D