I just wanted my printed spools to look closer to the spools I got from Bambu and to use a little less material. So I added holes into the spool and I also added a banana clip to hold the filaments end. It might have been better for me to print the clip separately and add it in later but I liked this style for now. This version I made for JAYO cardboard spools as they were much tighter than bambu refills to fit.