In partnership with our friends at Sinewave Cycles, we are proud to offer the Reactor Stem Cap USB Charger. Charge any USB device when you are on the go - cell phone, GPS, headlights! The Reactor 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, black and red. The Reactor is compatible with 1" and 1 1/8" threadless systems.