The MakerBot oversize XXL PLA filament spools are designed for hardcore professional printers who want to maximize the build volume of their 3D printers. These spools are designed specifically for the MakerBot Filament Case, which holds one XXL spool or two XL spools. PLA Filament Features Compatibility: MakerBot Replicator Z18 with Filament Case Diameter: 21.59cm Filament Diameter: 1.75 mm *The XXL spools do not fit inside any MakerBot 3Dprinters. They are designed to sit outside the printer.