I bought a dozen when I found them on sale that way and mounted them on three different lengths of pipe: 28", 40" and 52".  That way I have 2', 3', and 4' clamping CAPACITY with each.  I also threaded both  ends of the pipe, so with 3/4" pipe connectors, the possibilities are  expanded.  I do use wood strips to pad the jaws, otherwise they can damage  wood under pressure.  I have mounted them backwards on the pipe and used  them to spread joints a couple of times.  With a simple 2x4 rack, I can  glue up wide panels with them.  You need a few of these in your shop, too.