The product is a set of 4.5 inch flap discs, 5/8-11 thread specifically Type 27 with a Z40 grit. This set includes 10 pieces of flap discs manufactured by EncoreUnited Abrasives, with the abrasive material being Zirconia Alumina. These discs are designed for metalworking and sanding applications, providing high-quality and durable performance for various industrial uses. Made in the USA, this product ensures quality and reliability for your metalworking needs.