You can buy fancy ones, or make them from scrap. This one is preindustrial. I first saw one like this in my mentor’s shop. Unlike most it’s a single piece of wood -a moments work on the bandsaw, perhaps four with a handsaw. It hooks over the bench or in a vice and holds small stock while I finish plane it. As old shops get cleaned out most of these are consigned to the kindling pile. But, as humble as it is, it’s as at home in an 18th-century joiners shop as a modern one.