Grip-It looks like a plumber's strap wrench, used for tightening plated pipe and similar things. Imagine, for instance, putting the pipe for the showerhead into the wall fitting.
I have pretty much the same tool from Ridgid. Right handy at times.
In use, you loop the plastic strap around the thing to be tightened/loosened/moved (or "pipe" for short), and thread it back through the links holding strap to handle, with the free end closer to the handle. Orient the tool so that, when you're turning the pipe in the direction you want, the ramp on the end, next to the links, will be pressing against the pipe. If you can, make the loop first by threading the strap through, then slide it onto the pipe. Now, pull the strap tight, and fold the free end down along the handle. Grip strap and handle together, and turn.
If you fiddle around a bit, this is more intuitive than it sounds.
