The City Rover Io set consists of the City Rover 700 lumen USB-rechargeable headlight and the Io USB-rechargeable taillight. The City Rover 700 has a powerful lithium-ion battery and a darkness-destroying CREE LED bulb with side illumination. The Io has 3 different modes--steady, flash, and pulse--and is perfect for urban riding. - Both lights are USB-rechargeable - Io runtime up to 20h, City Rover up to 36h on daytime flash modes - Headlight has 5 modes for 2-36h run time - Headlight has additional 15 minutes in low-power safety mode after low-battery indicator light comes on - Headlight wakes up in last mode used - Taillight mounts vertically or horizontally - Headlight 125g, taillight, 53g