1. Flat/Turbo Fiber Disc2. Use: Iron, Non-Ferrous Metals, Alloy Steel, Stainless Steel, Wood, plastic3. Size: 4", 4.5", 5", 6", 7" Fiber Discs, turbo Fiber Discs are designed for aggressive grinding with a right angle grinder. The disc is constructed of industrial-grade backing paper for tear resistance, and premium..