Home » headsets » Integrated Headsets » r520a INTEGRATED HEADSETS R520A Height Adjustable +0~7mm IS42/28.6 | IS52/40 Alloy Sealed Bearings 1-1/8″ to 1.5″ Top Nut: 1-1/8″ Bearing O.D.: 41.8/52 Crown Cone: 39.8 Height: 26.5(33.5) Technical Diagram