Cycle2Charge v2 Dynamo USB Stem Charger Integrated Charger for Bicycles equipped with a Dynamo Hub Universal: Safely charge your iPhone, Android, GPS or any other USB device 5V USB Voltage: 500mA Output at 8mph & 1000mA MAX Output at 13mph! Can be used in conjunction with most Dynamo Lights Impact Resistant & Waterproof with spinning top shell to conceal and protect