this is a park bicycle work stand. it is awesome their isn't a part of the bicycle you cannot get to with ease and you don't have to stay bent over to work on it. it has jaws that clamp on any post on the bike including the seat post. then you can rotate your bike like a propeller to the position that is best for you. here is a picture of both sides to give a good idea what a great tool this is. just click on the thumbnails and pictures should be full size.