To attach your Burley Trailer to your bicycle, you will need the Steel Hitch. This hitch easily installs to the rear skewer of most bikes, and stays attached, so that the Burley trailer can be connected at any time. This hitch is compatible with QR axles and solid axles up to 12mm. For use with multiple bikes, we suggest grabbing a few spare hitches to remain on the extra bikes for quick access.