This GRS® universal positioning vise makes it easy to keep your work centered under a microscope. This vise fits into the jaws of any GRS vise; clamp the bottom rail between the jaws to turn your vise into a positioning vise. Loosen the jaws of your vise to quickly re-center or move to another part of your work. This positioning vise includes a MicroBlock® rubber base, eight 3/32" pins (four steel, four brass) and an Allen wrench. A smooth, self-centering jaw system (1.3" max. opening) on the GRS® universal positioning vise makes it perfect for detailed engraving and stone-setting. The jaws feature a number of holes, making it easy to create custom configurations that securely hold your workpieces.