Industry Nine iRiX IS42/IS52 Headset : IS42/28.6 | IS52/40 Integrated Complete Green Bearing#-6903X Use XN-6130 for Hydra freehub

Use XN-6130 for Hydra freehub seal

Hydraulic Bottom Out Shaft Eyelet Standard Spring Adjustments Preload Damping Adjustments External rebound Low & High speed compression Hydraulic Bottom Out Spring Type Coil Primary Color Black Eye-To-Eye 250x72

With every push

See this explanation for details

Size 42t and larger will work with the Dura Ace 9100 power meter

Industry Nine iRiX IS42/IS52 Headset : IS42/28.6 | IS52/40 Integrated Complete Green Bearing#-6903X Use XN-6130 for Hydra freehubTECH SPECS Headset Position Complete SHIS Lower IS52 40 Steerer Tube 1 1 8 1. 5 Crown Race Diameter 40mm Headset Type Integrated S. H. I. S. IS42 28. 6 IS52 40 Material Aluminum Lower Cup 52mm Bearing Grade Stainless Steel SHIS Upper IS42 28. 6 Upper Cup 42mm Primary Color Green