Serfas TL-ONE Taillight The industry's most technologically advanced safety lights All lights are robs compliant and all testing is done in house More efficient leds & high quality lenses to increase brightness & Clarity One 1/2 Watt red LED and 2 additional LEDs 3 beam modes Universal Mounting bracket Batteries included. Burn time Steady = 22 hours, Flash = 70 hours Easy "no tool" installation