When I was setting up my Flashforge Creator Pro. I discovered the mounting diameter of the spool holder is larger than the filaments I had bought online. Fortunately, Flashforge provided two filaments that fit the spool holder. But eventually the filaments will run out, so I designed the spool holder that will fit the filaments I had bought online. The filaments are 1kg, PLA by Hatchbox and AMZ3D. Both have a mounting diameter of 30mm. I hope you found this thing useful.