This strap consists of an alloy cam buckle which has been sewn onto one end of a length of polypropylene webbing. To use the strap you push down on the tab and insert the free end into the gap which opens up in the end of the buckle. Pull tight and release to hold the webbing in place. In order to move the webbing you need to press down on the tab. This is a very strong buckle, rated at 250kg load.