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 Practical - Standard and medium size sanding bands Standard grit 120, 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 a better finish; In case the sanding band comes off from the mandrel during use, please make sure the drum has been screwed on tightly and is very close to the sleeve. Note: Please wear safety glasses professional 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