This is an item for business contractors. This product is especially effective for processing that requires precision using a precision cutting machine with an extra level of precision. Compatible Works: Metal; Compatible Material Examples: Precious metals such as SUS pipes, gold and silver; Abrasive Material: GC; Outer Diameter: 8.1 inches (205 mm); Thickness: 0.03 inches (0.8 mm); Inner Diameter: 1.0 inches (25.4 mm); Quantity: 25 pieces