I believe this is known as a 3 way adjustable precision vice. Along with the standard jaw closure you can move the two jaws left and right and also forwards and backwards. This is a well made heavy item, it weighs in at nearly 6.5kg. Jaws measure 82mm Total front to back with jaws closed 320mm Total front to back with jaws open 390mm Jaws open approx 70mm Total side to side 320mm.