Scrap Box V Block SA MAKER's done a very good interpretation of what is broadly known as an 'insert vise'; meaning that it secures a small part but depends on secondary clamping to remain in position.

Nowadays, most usage is wire/ sinker EDM's, and occasional tool grinding. Great sine vise substitute; [ie] simple lathe bits, like snap ring groove cutters. Twist main vise for side clearance, tilt insert for tip width. Far easier to generate cutters on one edge of a blank, than ordinary way by hand.