With max 500 led lumens and improved eye-catching warning flashing mode, TR500 maximize the ride's daytime visibility to a new level. The rear light comes with an intelligent brake sensor for urban riding and auto on-off function for convenient operation. There are also 5 other modes, 3 constant and 2 flashing modes, for various riding environments. It is easy to use with the USB-C charging port and compatible with round and aero seatposts.