The Trek Flare RT tail light is the ultimate daytime-visible rear bicycled light for road rides, daily commutes, and beyond. It features a bright, rechargeable light that can be seen from up to two kilometers away. An integrated light sensor auto-adjusts brightness based on your environment, making it easy to stay visible day or night. Details: Specifically designed focus, flash, and range for ultimate daytime visibility 90 Lumen interruptive flash pattern can be seen from up to 2km during the day Integrated light sensor auto-adjusts brightness to your environment Connect with compatible ANT+ devices for always-on, battery status, and wireless control Flash modes: 90LM-6hrs, 45LM-12hrs, 5LM-15hrs Steady modes: 25LM-4.5hrs, 5LM-13.5hrs Confidently ride through wet conditions with an updated USB port and IPX7 waterproof rating Battery save mode provides 30 minutes of additional runtime when battery life reaches 5% Includes Flare RT, rear Quick Connect bracket, and Micro USB charging cable