Schmidt SON 28 6-Bolt Disc Front Dynamo Hub
SON 28 is a hub dynamo universally approved for all wheel sizes from 16" to 29". The rated output is achieved in the 700c (622)-wheel at approx. 16 km/h (SONdelux at 19 km/h). Thus, SON 28 is recommended if a lot of light is required at low speed or when either devices are to be operated or their batteries charged.