ILQ 9 Classic bearings feature tighter tolerances then the ILQ 7 bearings and will provide thousands of miles of trouble free use, even if you occasionally ride through dirt or rain. ILQ 9 Classics go beyond ABEC rating in terms of performance, durability, design, and materials. Since ABEC only measures precision tolerance, ABEC 7 bearings can be made out of inferior steel as long as they are accurate enough. The all new 6 ball ILQ 9 Classic has only one standard: the best. ILQ 9 Classic bearings considers precision tolerance plus other variables like design features, lubrication, and quality of materials.