Packing list: 2pcs nema 17 42-34mm stepper motor with integrated Tr8x8 lead screw 320mm/12.59inch& cable length 250mm/550mm. Application: great drop-in replacement or diy Z axis of Prus i3 Mk3s 3d printer, no firmware modification needed. or can use on CNC Milling, Small Robotics, Stage Lighting, Laser Engraving, please double check the specification before ordering.