This is an adapter for the B-Rail system to attach an AirTag. Using the B-Rail system adapter, you can easily swap bottle cages and tool box containers. We sell additional parts compatible with the B-Rail system. Please take a look at our other listings. - Model: B-Rail System Adapter + AirTag Mount - Compatible Device: Apple AirTag - Color: Black - Material: PLA+ Plastic Thank you for viewing. Giant, Trek, Specialized, Cannondale, ScottBikes, Bianchi, Cervelo, Pinarello, WilierTriestina, Orbea, Merida, SantaCruzBikes, GTBicycles, FujiBikes, Colnago, Cinelli, PIST Fixed Gear Fixie Single Speed