Uhm, i have never seen one, but can try to imagine ..... in this position, if you place a tube in the hook and pull the handler, it act like a screwing / unscrewing tool, but this does not seem its main function (they have usually variable or conical holders, for take different sizes, where this one looks having a single size) ..... for the counterpart, if i shift the hook in the other position before place a tube in it, then "roll back" the handler, that black thorn on the side can be pushed on the side of the tube ..... in one sense, it can "punch" through it, in the other sense, it can make a circular "wall" track around it (i mean, like the tracks in where you place o-rings for joint two different sizes tubes) ..... in this case, the other tool may be used placing it inside the tube for avoid to deformate it ..... the hex key seem there only for unhook the black thorn (if the black cylinder in front is a hex setscrew) ..... can't imagine other, for now, sorry.