Zipp: Sram Rear Caps Hub has 11-speed XD driver body. Axle made of tapered aluminum. Tapered aluminum axle is stronger without added weight. Fits all axles types. Ratcheting up the smarts. Finish: black, red and sand blasted; black, silver and polished. This straight-aligned, 4-pawl design turns the 26-tooth ratchet ring into 52 points of contact. The result: smooth 6.9-degree engagement without reducing tooth size or offsetting internal geometry-which means serious long-term durability. The only adjustment theyll ever need was made back at the factory. Every part of the ball bearing comes from the exact same supplier-which means that each bearing bore can be precision machined to fit the bearing race exactly. With tolerances this tight, the days of adjusting play after every ride are over.28 or 32 spoke holes11-speed XD driver body12 x 135 mm through axleGlossy black with silver accentsSand-blasted black with red label