Blade Thickness 5 mm Inner Hole 22.23 mm Outer Diameter 4 in. /100 mm For Use With Granite , marble, natural stone, concrete walls, slotting or leveling, polishing, etc. Use Dry / wet Ring Adapters 20 mm and 16 mm Maximum Speed Over 8500rpm, maximum rpm 12000. Tool It fits on any grinder that has a 4 in or 4.5 inch capacity With ring adapters to 20 mm and 16 mm. Special style 12 segment-wheel for curved surfaces and small-plane grinding and polishing. Two circle of grooves design facilitates dust removal and reduces the work difficulty. Classic cup-style wheel. Ideal for all types of stone This two-ring fluted design diamond cup wheel removes materialfaster and is ideal for all types of stone such as concrete, ceramic,tile, marble, granite, rock, cement, etc. Wood can be grinded? No, it's for Stone How many feet does this grinder cup typically work? It's usually over 200 square feet, better performance on hard materials. What is the grit of this mo fo? Diamonds dont have 'grit'..Its imbedded in the metal. Depending how much water you use..determines the finish. What is the maximum rotation speed of the grinding wheel? Over 8500rpm, maximum rpm 12000. More recommended products in our store Diamond Grinding Wheel Add to Cart Circular Saw Blade Add to Cart HSS Circular Saw Blade Buying Options Wool Felt Buffing Wheel Buying Options Diamond Polishing Pads Add to Cart Customer Reviews 4.5 out of 5 stars 371 4.5 out of 5 stars 468 4.1 out of 5 stars 142 4.4 out of 5 stars 141 4.3 out of 5 stars 30 Price $14.99$14.99 $23.99$23.99 — — $39.99$39.99 Diameter 4inch 3inch 3inch 5inch 2inch Thickeness 5 mm 1.8mm 1 mm 12 mm 3 mm Max Rmp 12000 Rmp 19500 Rmp 19500 RMP 20000 RMP Recommend 3500 - 5000 Rmp Inner Hole 22.23 mm 10 mm 10 mm 22.23 mm 8mm Features Dry and wet cutting Long service life Cut quickly with fluent swarf Sturdy and wear-resistant Wear-resistant