Another way to secure the filament to the reel while being stored. These are very snug fit to the rim, with the filament sandwiched to the edge. Two files, one for Bambu/Sunlu G3 (0.138" / 3.505 mm rim width) and another for Kingroon (0.105" / 2.692 mm rim width). These are the ones I primarily use, will add more as/if I try others.