Set Includes: 240 pieces sanding bands in 3 diameters: 1/2", 3/8" and 1/4", 80 pieces per size and 12 pieces sanding drum in 3 diameters: 1/2", 3/8" and 1/4", 4 pieces per size; 252 pieces in total Practical：Standard size and standard 120 grit sanding bands, used for smoothing surface and curved edges, polishing soft and hard materials, such as DIY, artwork and woodwork Easy Installation: Drum mandrels with self-expanding rubber cushion, making the sanding bands close to the mandrel firmly and achieving better finish; In case the sanding belt comes off from the mandrel during use, please make sure the drum has been screwed in tightly and is very close to the sleeve. Note: Please wear professional safety glasses to protect your eyes, because there may be some lump particles when the sanding drum rotates at high speed; the sanding drum will be attracted to the metal surface faster, please replace the sleeves timely in order to achieve the best sanding effect Bonus: Comes with a free