ILQ-9 Classic bearings feature tighter tolerances than 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.