Brake & ambient light sensor USB rechargeable 150 lumens brightness The MAGICSHINE Rear Light - SeeMee 150 is the perfect addition to any cyclist's safety gear. With its brake and ambient light sensor, it automatically adjusts its brightness to ensure maximum visibility. The USB rechargeable feature makes it easy to charge on the go, while the 150 lumens brightness ensures that you are visible from a distance. Its compact and lightweight design makes it easy to install and remove, making it a versatile accessory for any bike. Stay safe and visible on the road with the MAGICSHINE Rear Light - SeeMee 150. The SEEMEE 150 TL is an intelligent tail light that offers smart integrated sensors and enough brightness for both daytime or nighttime riding. It uses transparent optical filters to spread the beam 260 degrees, the maximum output can be reached up to 150 lumens. It has an integrated motion sensor, which reacts immediately and makes the tail light brighter when you hit the brakes, provides additional safety. It also features an ambient light sensor. When switched to the smart mode, it will switch between daytime to nighttime modes automatically. It is super simple to operate. A long press of the switch will turn the light on and off, and a short press will cycle through the modes. The seat post mount consists of a Garmin-type head, which the light clicks into securely, suitable for seat posts 22-35 mm diameter. There is also a saddle rail clip for those wanting a really sleek bike-mounted option. With the convenient Micro-USB port, charging is very straightforward and takes 1 hour to fully charge. And its IPX6 rating for weatherproofing is reassuring.