ILQ9 Pro bearings feature the speed of the ILQ9 Classic bearing without the extra weight of two bearing shields. ILQ-9 Pro"s are protected by a specially designed S-channel rubber shield. The SCRS presents an even more complex entry path for moisture and contamination. It is 95% effective at keeping the bearing clean. A nylon retainer on the inner face is shaped like a crown and is easy to remove and replace for servicing. The ILQ-9 Pro is the highest performance ILQ on the market and features a one sided rubber bearing shield which provides superior protection from contamination and do an even better job at keeping light oil lubricants inside. ILQ-9 Pro"s 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 Pro has only one standard: the best. ILQ-9 Pro bearings considers precision tolerance plus other variables like design features, lubrication, and quality of materials.