Lezyne Femto Drive Rear Light Black/Hi Gloss, One Size

Lezyne's Femto Drive Rear Light is designed to live quietly on your bike until its called into action by a quickly-sinking sun or a few wrong turns. It runs on a CR2032 watch battery, and will run for up to 60 hours on flashing mode, so a couple hour-long runs home in the twilight won't mean remembering to replace the battery.