●This product is ordered by the lot. Purchase unit: 5 pieces; High safety (European safety standard EN13743); Low vibration, high grinding power; Can be used on curved surfaces; Beautiful polishing surface; Metal grinding; Polishing and polishing; Paint and rusting; Outer diameter: 3.9 inches (100 mm); Grain size: #): 1.6 inches (40 mm); Hole diameter: 0.6 inches (15.0 mm); Blade length: 1 mm); Blade length: 1 mm). Maximum speed: 1 inches (2 mm). 100 Blades. Number of sheets (sheets): 72; Maximum usage speed: 63m/s (outer diameter 3.9 in (100 mm), 27.6 ft (80 m) / s outer diameter 4.9 in (125 mm)); Aluminum sharpening material