SummaryThis spool holder relies on a friction locking system to secure spools of filament to a wall. The spool holder system can hold spools with a spool diameter of 1.275" or larger, and 3.6" deep. The stopping circle has a diameter of 2.5" Depending on your print quality, the lock will be very tight! In my case it takes some effort to separate the two pieces, which reassures me the spool won't fall off the wall. FilamentChallengeInstructionsExtruder 220 degrees celcius Platform 110 degrees celcius