W2 Filaments cardboard spools consist of 100% recycled cardboard. Due to the double glued sides a sufficient stability is guaranteed. Circumferential slits allow the filament end to be fixed in any position and without damage for loss-free ongoing printing. With a standard 52mm center diameter and 200mm total diameter, the spools fit to most of the 3D printers. The spools are available in 4 sizes for fill quantities from 250g to 1000g.