Allows you to mount a standard industrial sprocket with a 5/8" keyed bore on a scooter motor that has a 8 MM mm shaft designed for a 10 mm double D bore sprocket. You may have to use the step file and adjust the different diameters based on how your printer performs. The adapter is modeled a little too big to account for ABS shrinkage and my printer under-sizing holes. Watch the video to see how to use this adapter.