1. Equipped with 5 diameter seat tubes, 31.8mm/28.6mm/27.2mm/25.4mm/22.2mm, suitable for all kinds of mountain bikes 2. Hidden locator reflective taillight bracket is not easy to be found and protects your car from being stolen.3. The reflective taillight is adjustable up and down, making driving safer at night.4. Material: plastic 5. Note: The product is only a tracker taillight bracket and does not include a GPS tracker
