Here's what Omnium has to say:

A human powered light generator!

No more bike light hassles like recharging them, removing them when leaving the bike, and getting caught in the dark with out them!

Available for V3 and WiFi bikes.

A complete front wheel. 

• • • Shutter Precision SP Dynamo Hub PD-8X, 6V 3W, K961, 400-536mm
    • 15mm Thru Axle for WiFi, V2 & V3 Frames
    • Sealed bearings
    • 32 spoke
    • Black V3 rim
    • Black stainless steel spokes
    • Brass nipples
    • 6 bolt disc mount

Lights, wires, disc rotor, tyre and tube not included.