Comprehensive Filament HolderThis is a filament holder that accommodates a large range of loose filament spools.The HUB can take upto 12 arms, although I usually use just 3 or 4 depending on the filament. There is a choice of 2 arm lengths, a long or short ( I tend to just stick with the long arms) and when combined with the 2 spacers allows for a large range of diameters to be held.Additional Spaces can be used to suit requirement if using my Dovetail Mounting system you can mount the spindle off of the top edge of the UM2.The fingers swivel open to allow for the filament to be easily loaded. if weak a small length of filament can be used through the finger hoop to keep it closed or the loose end of the filament can be held to keep tidy.the fingers and spacers all locate into each other and retain. Watch out for sharp edges on the Dovetails etc. when cleaning up and remove sharp edges to suit, I printed everything at 0.1mm step and used PLA and XT.