Filament Spool for Small Filament Amounts

I bought a multi-pack of PLA filament for a 3D pen and needed a way to spool it out for my printer. I use a lot of Tianse PLA and have setup my printer with a spool holder for the size of the Tianse rolls, so I decided to make a small spool holder that is the same width as the rolls I typically use (so I don't have to adjust my spool holders).

I designed it so that one end pops off so it is easy to load and unload the filament samples. I also like the spools that have holes in them to threa