【Double Gear Extrusion Mechanism】:The filament is gripped by the dual drive much more firmly with less deformation, so it doesn't jam as much in the tube, nozzle or hotend. | 【Upgraded Idler Gear Design】This idler gear is upgraded with two washers on both sides, so the sharp gear will NOT ride against the bottom of the arm or chew it up. | 【Spring Adjustable Extruder】The extrusion spring tension could be adjusted by tighten the screw,which greatly improves the printing accuracy and feeding issue. | 【Application】:This all metal dual drive extruder is compatible with Ender 3 V2,Ender 3 Pro,Ender 3,Ender 5 Pro,CR10 S series 3D printer. | 【Kindly Reminder】:Please calibrate the E-steps from 100 to 139.