Automatic Light Intensity The faster you go the brighter Varia UT 800 will be, watch out for those hazards at higher speeds. When connected with a compatible Edge cycling computer, GPS speed is used to automatically adjust the intensity of the headlight’s beam. At 800 lumens the Varia UT 800 is certainly bright enough at higher speeds for obstacles that may be in your path. Additionally, at lower speeds, the intensity of the light is lowered to conserve battery life. Day or night, road or trail – it’s time to step up to a smarter bike light. In the Box: Varia UT800 smart headlight, Charging cable, Universal out front mount, Quarter turn to friction mount, Manual KEY FEATURES: Multi Purpose Use: High-intensity cycling headlight for urban and trail use. Lumens: 800 lumen output that stays brighter, longer than the competition. Five Light Modes: High / 1.5hrs Medium / 3.0 hrs Low / 6.0 hrs Night Flash / 6.0 hrs Day Flash / 20.0 hrs Low Profile: New low profile design offers a sleek yet powerful design at just 130g ANT+® Compatibility: Wireless connectivity to Garmin Edge computers allows the context of the riding conditions to be used to control a network of lights that enables features like Auto On/Off, brightness control, display of light mode to Edge and automated power management. High Visibility: Visible in daylight from more than 1 mile or 1.6km Adaptability: Attach to handlebar with out-front mount or helmet with a helmet and friction mount. Vast Garmin Ecosystem: 2.5 million compatible devices in the Garmin network.