Chris King Boost 6-Bolt 148x12 rear hubs are designed as precision mountain tools. We use one-piece solid axles to provide a stiff hub that helps your suspension perform better and drive every watt of power into the dirt. To thwart mud, water, and contaminants as you power through rough trails, Boost 6-Bolt hubs have heavy-duty bearing seals and a threaded driveshell seal ring. Our bearings, available in steel and ceramic, have heat-treated, surgical-grade steel races that are machined simultaneously with tools of equal wear to ensure perfectly matched inner and outer races. The quality and speed of our bearings are what set us apart from the competition, and they are what you will feel and notice on every single ride. As Chris King bearing tracks burnish, they get faster with age, and all our hubs and bearings are fully serviceable for years upon years of demanding use. The patented Chris King RingDrive with 72 points of simultaneous engagement will get your power to the ground fast, provide unmatched engagement, and give you that legendary Chris King “angry bee” sound. Engineered, manufactured and assembled in Portland, Oregon, USA King Lifetime Warranty Canted flanges for stronger wheel builds Patented RingDrive system with 72 simultaneously interfaced points of contact for unmatched hub engagement Legendary made-in-house bearings Come in 28-hole and 32-hole drilling Available with Micro Spline, HG, or XD driveshell. Easily serviceable with a T10 and pick or pen knife Completely rebuildable with our Universal Hub Service Tool Responsibly lightweight Ceramic bearing upgrade available Specifically designed for "BOOST" 148mm x 12mm axle standard Hub Specifications Axle Width: 148mm Flange Diameter DS & NDS: 57.4mm Center to Flange DS: 23.8mm Center to Flange NDS: 36.3mm