Features: Integrated shaft-ensures better concentricity of gears and reduces eccentric rotations,ensure more uniform transmission of filaments by gears; Hollow pom gear with high transmission ratio, achieve greater extrusion-torque; The gear adopts double ball-bearings, resulting in smaller clearance and higher-accuracy; Hardened steel gears with nickel plating treatments, improving the durability and reliability; Not fit for sherpa-extruder; There are many product on the market that can be equipped with bm gears due to differences in dimension and tolerances,the filaments inlet can be aligned by squeezing the black large gear to move the position or add shims to the shaft-; Specifications: Material:Hardened Steel for BM/VORON 0.2 Extruder; Note: Please allow 1-2cm errors due to manual measurement,please make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1set POM Gear