Home » headsets » internal cable routing » r554a INTERNAL CABLE ROUTING HEADSET R554A IS52/28.6 I EC49/40 Alloy Cap/Cup Sealed Bearings Top Nut: 1-1/8” to 1.5” Bearing / Cup O.D.: 52/49.6 Crown Cone: 39.8 Height: 27.8 Technical Diagram