This Trizact™ disc from 3M is ideal for your Dura-BULL® polishing and flat lap machines and for any application that accepts a 5" disc. Trizact micro-replicating technology wears evenly for long bench life, and its unique abrasive surface cuts stone and metal smoothly without pressure, reducing buffing and tumbling time. When run wet, disc's cerium oxide is activated by the water to form a slurry that produces a beautiful final polish. Though the abrasive is 0.5-micron, it produces a finish as fine as you can get from 0.25-micron, due to the Trizact design. To attach, simply peel away the backing paper and press the disc in place on your wheel or pad.