It is also perfectly possible to take many of the old lights and inexpensively convert them to LED for greater output for those with some familiarity with electronics who want more light from the old Dynamo headlights. One big advantage of most of the commercial LED dynamo lights is that they have a "Standlight" that gives some light when stopped. Sturmey Archer made a D cell battery holder, which held 3 or 4 cells, for the same purpose that was used by Raleigh and other British makers on some of their hub dynamo bikes.