Premium and Value Materials - GRASSLAND cutting discs are made of aluminum oxide grains that are durable. It also provides aggressive cutting action and longer service life. Safety Certificate - Reinforced by double fiberglass mesh,meet MPA en12413 standard. Perfect Size - Outer diameter:4.5inch inside diameter:7/8 inch,045" quality thin, operating up 13,000 RPM and 80M/S. optimized for 4.5”angle grinders. Multiple Applications - Tough abrasive cutting discs are perfect for super-fast, clean cutting in carbon steel, stainless steel, pipe, iron, copper and all other ferrous metals. Precise and Efficient Cutting - Design for fast burr free cutting with minimal material loss, make cutting project more precise and efficient.