Universal Stainless Steel Extrusion Gear*Type: MK7 extruder gera *Printing Type:3D *Material: Stainless steel *Use1: 3d printer extruder*3D Printer accessory MK7 Driver gearThis stainless steel MK7 drive gear is the industry standard filament drive gear good for all kinds of filament but it excels with "hard" filaments like PLA5mm Bore Fits Most NEMA 17 Motor ShaftsIncluded Set Screw Secures Gear to Shaft Sharp Teeth Optimized for Harder Filaments