Package Contents - Comes with 504 sanding belts, 24 sanding drum mandrels, 2 self-tightening drill chucks, and 1 combination wrench, 1 set totaling 531 pieces Essential Accessories with 7 Grits - These sanding belts are available in 6 grits (80 grit, 120 grit, 180 grit, 240 grit, 400 grit, 600 grit) and 3 diameters (1/2 inch, 3/8 inch, and 1/4 inch). 24 belts are available and replaceable for each grit and size Universal Drum Mandrels - 24 reusable drum mandrels in 3 diameters: 1/2", 3/8", and 1/4", 8 of each size. Universal and standard sizes for all tools Rotary Tools EASY TO INSTALL - Make sure the drum is tight. The drum spindle is equipped with a self-expanding rubber pad, which keeps the sanding belt firmly close to the spindle and achieves a better finish. Note: There may be some flying grain when the sanding drum rotates at high speed. Please wear professional safety glasses to protect your eyes. Wide Compatibility - Standard and standard size drum sander set, widely used for