Shimano Alfine & Nexus Dynamo Front Hubs 6V, 3.0W output. Centerlock rotor mount. Compatible with 26 to 28" wheel sizes. Light alloy QR lever and nut. Rotor lockring not included. Item Specifications: Color, Black, Weight, 635, Hub Drilling, 36, Defined Color, Black, keyword search, dyno, keyword search, generator hub, Front Axle, QR x 100mm, Hub/Brake Compatibility, Center-Lock Disc, Center to Flange, Left, 20, Center to Flange, Right, 28.5, Flange Diameter, Left, 70, Flange Diameter, Right, 70,.