Alpha® has developed a new series of polishing discs specifically designed for polishing concrete countertops. The Alpha® 4-Step Concrete Polishing System includes 4 Semi-Flexible Discs. Each disc is laminated with rubber and equipped with the Variable Drive System for better control during polishing.Steps 1 and 2 use Semi-Flexible Metal discs which have a metal bond that prolongs the life of the disc thus improving the overall cost of polishing. Steps 3 and 4 use the Semi-Flexible Resin discs which provide the best possible professional finish on concrete without the uneven surface. These discsare easily changed for increased production capabilities. The Alpha® 4-Step Concrete Polishing System is a winning combination of cost-effectiveness and superb results! 4-Step, Concrete, Polishing