Super bright 30 lumen cob rear light with saftey brake light funtion the light will automatically detect the riders speed slowing and shine birghter under braking or glow constant under braking when in flash mode micro usb rechargingweight lumen output 30burn time high 8 hours med 9 hours flash 12 hours strobe 12 hoursusb rechargablewaterproof ipx5lithium ion batterycolour black