Gen 4 axles for Chris King rear hubs. These axles are compatible with Gen 4 Driveshell parts and adjusting clamps only. 130x9mm compatible with R45 hubs. 142x12mm compatible with non-boost ISO and R45D hubs. 148x12mm compatible with ISO B and Boost Centerlock hubs. 157x12mm compatible with ISO DH Gen 2 and Superboost Centerlock hubs. Available in Silver or Black. Contact info@chrisking.com with any compatibility questions.