Modes include HIGH STEADY, MEDIUM STEADY, LOW STEADY, DAYTIME PULSE, NIGHTTIME PULSE and ECONOMIC FLASHFULLY USB RECHARGEABLE No batteries to buy or replaceRun time up to 24 HOURSSide illumination ports allow cyclist to be seen when riding across traffic lanesMemory Function-Light turns on at the last mode it was turned offPower saving function- 10% power or less, lights will automatically switch to lowest lumen output