The original was designed by an Australian chap, they are sold as 'Triton Superjaws' I bought one a few years ago for about £80, they are fantastic, the movable jaw is reversible to hold very large items.
I have a welding bench top I made which is held in this device when I need to use it, and slides under the workbench when not needed.
It can squeeze things together with an impressive amount of force.
They do a couple of different versions.
Highly recommended.