BLACKBURN Central 20 USB Rear Bike 2 super bright LEDs push out a 20 lumen safety beam. Translucent bezel amplifies side visibility Large lens power button is easy to turn on/off while pedaling or wearing gloves Lumens: High 20, Flash 20, Strobe 20 lumens, Runtime: High 25hours, Flash 42hours, Strobe 76hours Flexible silicone mount fits all seatpost diameters and shapes The lights thin profile easily stows small in your pocket