Check the listing for details. DeerFos - 3" TR 80 Grit Quick Change Disc Zirconia Alumina - 25 Ea Box. Condition: New. Listed at 19.95 USD. DeerFos - 3" TR 80 Grit Quick Change Disc Zirconia Alumina - 25 Ea Box Zirconia Type TR Quick Change Surface Conditioning Discs mount easily and stay in place securely. These heavy-duty Y-weight poly discs are great for stock removal and grinding of ferrous metals, non-ferrous metals and stainless steel. Mount on any pneumatic grinding tool or even your power drill! Discs are coated in a stearate grinding aid to reduce heat and resist loading. We use a plastic mounting system to eliminate any issues with rusting or degrading over time. Due to their excellent performance in moderate to heavy pressure applications, these discs are our first choice when grinding gummy, heat sensitive metals. Recommended for: aggressive stock and weld removal, non-ferrous metals (aluminum, copper, brass, etc.), ferrous metals (iron, steel, etc.), composites and stainless steel*Premium Zirconia Alumina Grain*Resin bonded and coated with a stearate grinding aid to reduce heat and loading *Ballistic grade nylon buttons remove the risk of corrosion in metal fastening systems *3" Dia 80 Grit *Type 'TR' attaches to Lockit™, Powerlock III™ and 3M™ roloc TR™ mounting systems