Giant's Numen Aero Taillight is small, powerful and impressively bright. It's so sleek and light that it almost disappears. Come nighttime, though, cars will notice its three bright LEDs. It has a run time of up to 90 hours and features three modes: steady, flashing and chasing. The tool-free rubber mount easily attaches to most seatposts, including aero and integrated models.
Requires 2 CR032 batteries