Bicycle rear light installation location: seat post Specifications: Light source: COB LED integrated, using 26 high-brightness chips. Color: Red/White. White on the front, red on the back. Model: Low light---medium light---high light---50% high light---100% flash---stroboscopic Charging: USB charging (Android interface) Usage time: 3 -6 hours Suitable for: seat tube diameter 15-32mm Mode switching: 1. Press the power button in the off state to select 3 always-on modes. 2. Press and hold the power button in the off state to select 3 flash modes. Features: The shell is made of 100% new PC ABS material. It is equipped with gel tape and has a wide range of applications. It is easy to install without any tools. It is easy to install and carry. Fits most bikes. Package includes:: 1*Bicycle light tail light Note: 1. Please allow a little error due to manual measurement. Please make sure you don't mind before bidding. 2. Color may vary due to different monitors, please understand. Hello, please pay attention to your delivery address when purchasing products. If your delivery information (such as name, street, house number, doorbell/mailbox without name, etc.) is incorrect, the order will not be delivered correctly.)