The Norton Gemini Fiber Disc is a high-quality sanding disc featuring a 4-1/2 inch diameter and 80 grit aluminum oxide coated abrasive material. These discs come in a pack of 25, each with a 7/8 inch arbor hole for easy mounting. Made in the United States, these fiber discs are durable and designed for efficient sanding and grinding tasks in metalworking applications. With the trusted Norton brand and quality construction, these discs are reliable tools for various industrial and manufacturing projects.