10 pcs 0.3mm 3D J-Head hotend/E3D extruder Nozzle Drill Cleaner, if you need other size like 0.35mm 0.4mm , pls order this , but write a comment for your order , need 0.35mm drill instead
A Hobbed Bolt is a part seen in about any geared extruder design such as Wade's Extruder. Its sharp teeth outright bite into the filament, allowing high transport forces.