This parametric design allows you to cut off any brand cardboard spool walls, slide in this adapter and then slide everything onto the Bambu reusable spool. Just align the notch to the nib on the spool and you are good to go. Please edit the diameters in Open scad. The Default parameters are made to fit Inland brand Abs to the oem Bambu spool, 90mm outer diameter 82mm inner diameter.