Planet Bike Blinky 3 bike tail light 3 5mm LEDs and built-in parabolic lensing provide steady & flashing modes FL1 Tested - Run times: 10 hrs (steady  4 lm), up to 100 hrs (flashing  4 lm) Provides 140 of visibility 2 AAA batteries (included) Includes seat post and seat stay mounts and clip mount for multiple mounting options