Home » headsets » internal cable routing » c660a Semi-internal Cable Routing Headset Installation INTERNAL CABLE ROUTING HEADSET C660A WATERPROOF ZS56/28.6 | ZS66/45.8 Alloy, Sealed Bearings 1-1/8″ to 1.8″ Tapered Head Tube & Steerer Top Nut: 1-1/8″ Cup O.D.: 56/66 Crown Cone: 45.8 Height: 11.2 Weight: 175g Technical Diagram