Quantum Bearing Science Metallic TJ Rogers SeriesAs part of TJs signature bearing development process, we wanted to design a bearing that matches his style smooth & fluidic while also allowing the bearing to keep this performance under high impact and tough terrain Features: Precision design throughout the bearing High quality chrome steel Ultra strong composite retainer cage Precisson fit, non contact shields 8 x metallic Series bearings 16 x metallic Series bearing shields with micro ring for easy