Package includes - comes with 180 pieces of sanding bands and 12 pieces of sanding drum mandrels. Totally 192 pieces drum sanders set with free plastic box, convenient to store and search Essential 3 grit accessory - these rotating sanding belts contain 3 sanding grits (80 grit, 120 grit, 240 grit) and 3 diameters (1/2inch, 3/8inch and 1/4inch). and size Universal Drum Chucks - 12Pcs reusable drum chucks which in 3 diameters (1/2inch, 3/8inch and 1 /4inch), each size 4 pieces Common and standard size suitable for all rotary tools like Dremel etc Easy installation - make sure the drum was screwed in tightly, the drum chucks with the rubber cushion self- expandable, making the sanding strips close to the manderl tightly and getting a better finish; Remark: please wear professional safety goggles to protect your eyes, because there may be lump particles when the sanding drum rotates at high speed Wide compatibility - standard and standard size drum sander set which are widely applied in smoothing surface and curved edges, polishing soft and hard materials, such as renovation, artworks, woodwork and other DIY finishing and working