This hitch adapter by Burley was designed to mount a Burley Forged Hitch to bikes that have clearance issues on the drop out. The most common issue are Breezer style drop outs. Other issues could be racks or other non standard fixture or dropout setups.
This adapter is simply used to replace the nut on the end of any standard quick release or nut on a solid axle. After the hitch adapter is installed onto the hub, it functions identically to a standard quick release or axle nut. The bike trailer hitch is then mounted to the protruding threaded section and locked in place with the included nut.
While this part is manufactured by Burley for all of their trailers that mount to the Burley Forged Hitch, it also can be utilized for solving clearance issues at the dropout with any similar style hitch that mounts to the a bicycle rear dropout with a quick release. This include hitches by Chariot, Croozer and Radical Designs.
Please note: It is important to get the correct size for solid axle thread types. Have a local bike shop help you figure out the correct size if you do not know which one you need.