What's contained: you will get 6 set black 3D printer spool holders, 12 pieces separated holders, compatible with PLA/ABS/TPU/Other 3D printing materials Smooth bearings design: filament spool holder adopt the latest technology, the silicone anti-slip mats has better adhesion than before and the holders are not easy to slip; The filament spool holder bearings are covered with a ring to prevent the bearings from becoming stuck due to oxidation, and the bearing runs smoothly, reduces all drag on your 3D printer filament