Fully assembled, easy to install and use. SLS molding shell, made of PA, strong and durable Compatible with CR-10/4S/5S/MINI, CR10S, CR-20, Ender-2, Ender-3/PRO/V2, VORON 3D Printer E-axis step value of extruder needs to be modified. For example, the E-axis step value of Ender3 is 691 Drive current of the extruder needs to be adjusted to 0.35A (method: adjust the voltage to about 0.28-0.3V or firmware to adjust the drive current of the E axis) Reason for adjusting the current: prevent the motor from overheating Modification of extruder pulse method: Method 1: Firmware modify the extruder pulse: #define default_axis_steps_per_unit {80,80,400,691} Method 2: Send G code (can be sent by using Slicing Software command): M92 E691 M500