The spool holder's spindle is shaped to fit the vast majority of commonly used filament spools with shaft holes ranging from 16 mm to 62 mm in diameter. It is also compatible with spool-less filament coils. The spindle which holds the spool's weight rotates on its own roller wheels, which makes it turn effortlessly. The spool holder included an arm for filament guide tubes of both common sizes 1.75 mm and 3.0 mm. The arm also contains a pocket for inserting a piece of sponge which acts a a filament filter - thus keeping the filament clean and lubricated. FEATURES - Easy to 3D print - Needs no glue or fasteners - All parts can be 3D-printed - Fits almost any filament spool size - Has built-in filament filter! - Can also hold spool-less filament coils Next time you need a new filament spool holder, just 3D-print one! :) INSTRUCTIONS Please see video http://youtu.be/X6ArZeWYSZE