This is another old design making a comeback thanks to Lee Valley's Veritas Toolworks. The twin-screw vise was popular during the late eighteenth and early nineteenth centuries, particularly with chair makers. The updated Veritas design uses a chain to connect the two screws, keeping them slaved to each other. There is also a provision for decoupling the screws so that tapered work can be held. This design has many of the advantages of the classic shoulder vise and single screw face vise, with few of the disadvantages. It can also be used effectively as an end vise. The main drawbacks of the twin-screw vise are the expense and the relatively difficult installation.