The Lifeline Daylight Visible Rear Bike Light is a rechargeable 20 lumen unit ideal for day and night riding.Brightness is key for daylight riding and the Lifeline Daylight Visible Rear Bike Light has a 38 chip COB LED providing a blaze of illumination. This coupled with a purposefully disruptive flash pattern make the Lifeline light a great partner on the road. With 7 modes to choose from the rider can balance the road and light conditions against the most appropriate illumination. The light is Micro USB Rechargeable taking 2 hours to achieve a full charge.The light can be post or helmet mounted and comes with both a post mount bracket (fits 19-32mm dia) and a velcro helmet strap.Need to know how much battery is remaining? Simply double click on the light to show the remaining capacity. A constant light indicates 100-50% battery remaining, a slow flash indicates 49-25% and a fast flash tells you there's less than 24% battery remaining.7 Modes: High Beam (1.5HRs), Low Beam (4.5HRs), Flash 1 (20HRs), Flash 2 (5HRs), Flash 3 (7.5HRs), Flash 4 (15HRs), Daytime Flash (8HRs)Weight: 18gWater ResistantMicro USB ChargingBattery Level IndicatorLow Battery AlertMount: Post Mount fits 19-32mm diameter posts.