Z-Prime Poly-Cotton Zirconia Provides The Fastest Metal Removal Of Any Zirconia Based Grain In The Market. Z-Prime Tough Edge Is Designed With Compressed Design Technology To Provide The Optimal Grinding Angle. Z-Prime Provides Cool Cutting With A Built In Grinding Aid And Is Recommended For Aggressive Use And Heavy Duty Applications. Excellent On Carbon Based As Well As Stainless Steels.