The wedges and holders individually, loose and come complete without accessories, it is also no indication in how the key to be inserted into the likewise plastic holder and secured therein. Simply tuck does not work namely, and as the whole still is pretty hard, I had some anxiety, holder or wheel chocks to damage in the first experiments. But if we have found the first time, and has worried some suitable screws for fastening the holder on the trailer, the wedges are certainly serve their purpose.