The Bontrager Flare RT2 Rear Light’s 90 lumens output, can be seen from upto 2km away out on the road. The compact design, is entirely waterproof with its USB (Universal Serial Bus) seals to prevent water getting in. It features an integrated light sensor, where the light will auto adjust to the brightness surrounding you. Altogether, it has 5 modes which can all be controlled, monitored & connected to your Garmin & Bontrager ANT+ devices. A great compact light to have so your safe on the road, commuting or just out for fun.