'SATGURU' Levelling Jack can used as an adjustable support block for clamps and as a stopper or leveling block in fixtures or machines, as well as for levelling surface plates or other heavy duty work pieces. Its unique design does not allow the levelling screw to rotate while adjustment hence makes it suitable for fine level adjustment. It also has a heavier version of levelling jack with a heavy body and Levelling Screw & Knurled out. This Jack is specially designed for heavy castings & machines..