The Sinewave Reactor takes the performance of our Revolution dynamo-powered USB charger and shrinks it into a package that fits above the star-fangled nut in a threadless steerer tube, with a pass through for the 6mm bolt.  The only visible part is a custom CNC-milled stem cap holding the USB connector.  The cap is only 9.8mm tall and available in silver and black. The Reactor is compatible with 1″ and 1 1/8″ threadless systems.