This replacement pair of 15267 bearings are part of the ABEC-5 line, which are the revised LLU/LLB dual seal bearings. The ABEC-5 Dual Seal bearing places a LLU full contact seal on the outside facing surface of the bearing, while the Inboard facing LLB medium contact seal offers less drag. Their specific seal increases the lifespan of the bearings and offers excellent performance. High precision balls are within 5/1,000,000″ round. These are military level specification, used for precision equipment. R-64 hardness, of the highest grade.
This bearing will also fit many other hubs which use this size of bearing.
This superb bearing sets the benchmark for high precision bearings.
Instructions can be found here for bearing replacement in a 15mm Nukeproof front hub.