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. Easy to use: the filament roller is a pre-assembled holder, no tools needed, easy installation and quick installation, the bearings may be a bit stiff when you first use, please lubricate a little more and they will run well. Strong and durable: the 3D printing spool holder made of quality metal and plastic, stable and durable. Wide applicable: adopting quality material which creates a consistent free flowing spool that reduces all drag on your 3D printer filament. What's contained: you will get 2 set black 3D printer spool holders.