Set includes: 240 pieces of sanding bands in 3 diameters: 1/2", 3/8" and 1/4", 80 pieces per size and 12 pieces of sanding drum in 3 diameters: 1/ 2", 3/8" and 1/4", 4 pieces per size; 252 pieces in total Convenient - Standard size and standard 120 grit sanding belts, used for smoothing surface and curved edges, polishing soft and hard materials, such as DIY, artwork art and woodwork Easy installation - drum chucks with self-expanding rubber pad, making the sanding bands close to the chuck firmly and getting a better finish; In the event that the sanding belt becomes dislodged from the mandrel during use, please ensure that the drum has been screwed on tightly and is very close to the sleeve. Note: Please wear protective professional safety goggles to protect your eyes, because there may be lump particles when the sanding drum rotates at high speed; the sanding drum will be drawn to the metal surface faster, please replace the sleeves timely in order to get the best sanding effect Bonus - Comes with a free plastic box, convenient to store and search