Feature: 1. 3D printer pulley is suitable for Prusa i3 MK2/MK3, very practical and important 2. These high-quality parts improve the reliability of the 3D printer extruder 3. This is for Prusa printer's high quality atermarket parts and extruder gear components 4. The kit come with nuts, bearings and other materials, easy for you to install 5. 3D printer wire feeding wheel is simple to use, with high quality, sturdy and durable Specification: Item Type: 3D Printer Pulley Model: Pulley for i3 MK2/MK3 feed wire feed wheel Instructions: 1. Press the nut into the slot on both sides of the idler. 2. Insert the two bearings into the pulley, paying attention that the bearings may slip out during assembly. (Due to the geometric structure, layers may be seen in the printed part, function and strength will not be affected) 3. Make sure that both bearings are inside the pulley. 4. Insert the pulley into the idler. 5. Pass the shaft through the idler and pulley. Use reasonable force, otherwise the printed part will be broken. 6. Put your finger on the bearing to ensure that the bearing can rotate freely.. Package List: 1 x Pulley(with locking screw)1 x Pulley(without locking screw)2 x Pulley Bearing2 x M3NS Nut1 x Pulley Shaft