This is a clip for filament wire to be held in place in the roll. It will be clipped on to the filament roll and the filament wire will be inserted into the clip's hole. For futher questions for me, add them in the description or notify me. My youtube channel is 3D PRINTING HUB : https://www.youtube.com/@3DprintingNERD9977. Thank you so much for reading this and please print this out and leave a print profile.