Ritchey wheels equipped with the Zeta rear hub feature a simple, interchangeable freehub system. This item is the WCS level SRAM XDR 12-speed road freehub, and is available for specific wheels (see below). Machined alloy construction, high quality sealed steel bearings, and a ratchet-type engagement system deliver the performance and excellence you expect from Rithcey's WCS- level components