?Universal Design?This Airtag bike mount hidden is suitable for all mountain bikes with an inner diameter of the lower fork hole from 18 to 30mm. Configured with four different sizes of expander bracket, there is always one for you, feel free to ask questions. ?Bi-Directional Expander Design, Safe and No Displacement?Expander bracket for two-way expansion fixed lock, use without worrying about the natural inertia fall out, very safe, safe use. ?The Most Hidden Anti-Theft Device?The Airtag bike mount is hidden in the most inconspicuous place, mounted at the bottom between the forks of the front wheel. Who would have thought that the anti-theft Airtag would be hidden here?. ?Package Contents?1x AirTag bike mount, 2x EVA protective pads, 1x expander mount 18-20.9mm, 1x expander mount 21-23.9mm, 1x expander mount 24-26.9mm, 1x expander mount 27-30mm, 1x M3 wrench, 1x M5 screw and a screw cap. (AirTag Not Included). ?Product Specifications?Product weight:86g, Package size:8.2*8.2*3.2cm, Product material:Aluminum alloy + plastic.