Students always want to know what colors we have. When I tell them, then they want to know what those colors look like. So I needed a way to display the colors and be able to easily update availability of the different types. We are primarily using a MakerBot Dual to print with so we are using 1.75 mm plastic filament. This holder is designed for displaying that size plastic. I had a magnet that was 14mm in diameter and 6mm thick so I created the holder to accomodate that magnet. In addition to the .stl file, I've uploaded the .par file (created in Solid Edge) so that others might be able to make use of and modify this design to suit their own needs.Ours was printed with Glow In The Dark PLA on a Makerbot Dual. Support: None Needed Infill: 25% (recommending higher value... ours cracked removing from the bed) Shells: 3 Nozzle Temp: 180 Bed Temp: 0