The Specialized Stix Elite 2 Taillight is a powerful rear light to make sure you are seen by other road users day or night. With its spherical lens the Stix Elite 2 directs lumens more than a 1/2 mile (800m) even on the sunniest days, making the Stix Elite taillight the go-to taillight for year round training rides. If you are commuting, or just running late on a ride the Stix Elite 2 will also make sure you are seen at night. It’s all about peace of mind, really, & with its six light modes, you get multiple options for day or night visibility. & depending on the chosen mode, this taillight will run for up to 77 hours, & it’s easily charged via built-in USB (Universal Serial Bus) tab, which eliminates the need for a cable. Features 12 to 100 lumens output. Dome lens concentrates output from CREE XBD P4 center LED for 1/2 mile (800m) visibility in the brightest sun. Fresnel lenses for secondary LEDs provide wide angle visibility. 2.5- to 77-hour runtime. Charges in the USB (Universal Serial Bus) port of any laptop or phone charger in two hours (no extra cables needed). Flexible mounting system works with seatposts from 22.2mm up to 35mm in diameter, plus its compatible with most seatstays (Aero strap mount available separately).