KRY REAR AVENUE R-45 USB BLACK2 LED USB rechargeable tail light 5 modes, High steady, Low steady, Daylight pulse, Nitelight pulse and Economic Flash Side illumination ports allow cyclist to be seen when riding across traffic lanes Memory Function Light turns on at the last mode it was turned off Power saving function 10% power or less, lights will automatically switch to lowest lumen output Built in battery indicator Red illumination = lower than 25%, Green = fully charged