Features: Stealthy bicycles Fork Protector securely hides trackers inside mountain bike's steerer tube with precisions fit star nut compatibility, offering anti theft protection through invisible installation that deters thieves from detecting or removing the trackers. Features aluminum housing with anodized finish for scratch resistance and integrated silicone padding to absorb vibrations, while spring load expansion mechanism ensures wobble free stability during road cycling. Ideal for mountain bikers seekings tracking solution and security riders who prioritize maintaining their bike's original structure without drilling or modifications. Perfect for trails and urban commutes, this protector maintains full signal transmission through strategic ventilation holes, enabling accurate location tracking. The case is meticulously designed to provide a precise fit, preventing any loosening or rattling issues. Specifications: Component:Aluminum + Plastic Suitable for front fork with upper outer diameter of 28.6mm, expansion ranges: 21.5mm-25.4mm Package Includes: 1Set Bicycles trackers Holder note: Please allow 1mm errors due to manual measurement. Due to the differences between different monitors, the picture may not reflect the actual color of the item.