BE CAREFUL  We have provided pictures of others being sold here. They are made in China and will not work. The silver one is to long and too thick. It will never open properly The other one with the green or blue top is to short and will break your floor with a hard pull.  

Ours were developed 40 years ago my Bill Martin for Snap-On. They are cast steel with a special taper and a rough surface to lock fast. Plus these can be removed if you relocate. They are made in Texas by a foundry and finished by ProBSE,  Any question call or text  thanks