Summary This cylinder is designed to prop up the spool so it rotates around a smaller axis. This will allow filament to unwind with less friction. Its sized to fit just about any spool of filament. To use the cylinder, just insert each part on separate ends of the spool and twist to interlock them. It is made so a 1/2" all thread can go through the middle. Even though I would recommend this design for all materials, It is especially useful with flexible materials. It allows the material not to stretch as much when the extruder is trying to unwind the filament spool. Print Settings Printer: RepRap Anet A8 Rafts: No Supports: Yes Resolution: .2 Infill: 20% Notes: Supports should only be needed under each L interlock.