DH-3N72 6v 3. 0w quick release dynamo front hub for use with rim brakes - 36h. Specification & Features of Shimano DH-3N72 6v 3. 0w Quick Release Dynamo Front Hub. Light weight, high grade 6 volt 3 watt dynamo front hub with easy to use quick release. Provides bright illumination for safer night riding without the need and expense of replacing batteries. Important weight savings are made by using an efficient and light weight aluminium coil structure. For use with rim brakes. Labyrinth and contact sealing - low-friction seals and internal grease sleeve effectively shut out water, mud, and dirt without affecting rotational smoothness increasing service life. Borozon treated bearing races - super mirror finish bearing races reduce friction and provide a more precise bearing action. Push-in wiring harnesses make installation fast and easy. Anodised forged aluminium hub shell. Comes with an easy to use quick release skewer. Average weight 558 grams. Shimano DH-3N72 6v 3. 0w Quick Release Dynamo Front Hub is perfect for:. Night Riding.