TwinCam ILQ9 Classic Plus inline skate bearings are slightly different from the original Classics. The "Plus" version features a self lubricating nylon retainer on one side, and a metal shield on the other. Same 6 ball technology, just designed for easier cleaning. ILQ-9 Classic Plus bearings have a metal shield on one side and a Nylon retainer on the other. The metal shield sits in a L-shaped undercut and is held in place by a removable C-clip. The undercut helps to form a protective barrier that keeps lubricants in and contamination out. A nylon retainer on the inner face is shaped like a crown and is easy to remove and replace for servicing. 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.