This is a support for a Filament Rack. You can slide 1" PVC pipes through the holes and the filament sits neatly on top. If you have 12' rack you could use 4 of these supports. I use them in a dry box to organize my filament. You could also double stack the filament if you put the supports in the vertical position. I made it to the maximum size possible to print 2 on a print bed at a time.