320, 400, 600, 800, 1000, 1200 Specialty Polishing Stone · Treated Aluminum Oxide · Soft Structure with Fast Breakdown T4 is a specially treated soft aluminum oxide finishing stone that cuts fast and leaves an excellent finish. This stone is engineered specifically for aluminum and other soft materials. It will not scratch or tear the surface. It can be used either by hand with one of our Hand Holders or with reciprocating profilers like our U-Lap and Turbo-Lap Air Profilers. Must be used with a lubricant to prevent stone loading. Try our Premium Stoning Oil or BORI-LUBE 10! Available in 150-1200 grit and a wide variety of sizes. Also available in regular and fine grit kits. x