Use this clip to store your filament spool and prevent it from unwinding itself. Instead of clipping the filament the the spool itself, this clip is attached to the filament itself. Therefore it can be used with any kind of spool. The clip was originally designed for filament up to 3mm and is very easy to use. Depending upon the exact diameter the clip will easily slide over the end of the filament (see picture with the blue filament) or it can be put on the end of the filament as a kind of 'cap' (see picture with the yellow & red filament) If you want to use this clip for smaller diameter filament you can simply scale it down or download the 1,75mm version of it Update V2.1: Modified the STL file: Update clip175-v1.STL : I created a new version of the clip especially for people using 1,75mm filament. Simply download this version for your 1,75mm filament I printed a batch of 4 of these clips each time I switch the filament on my Ultimaker-2. I used the following settings in Cura to slice it: Layer height: 0.1mm Shell thickness: 1mm Botto/top: 0.8mm Infill: 0% Speed: 50 mm/s