PolyBox™ is a dry storage box designed to provide the optimum environment for 3D printing filaments. The PolyBox™ is compatible with all 3D printers and can house two 1kg spools or one 3kg spool. Printable desiccant holder by sworcester TPU add on by sworcester How many spools can fit in the PolyBox™? 2*1kg spools or 1*3kg spool from Polymaker. Does the PolyBox™ Actively dry the material? No, the PolyBox™ protects your material from absorbing moisture by storing it in a dry environment while printing. Can the desiccant bags be reused? Yes it can be reused 4 to 5 times, please follow the steps in the manual to dry the desiccant bags.