1) It is made of high quality cast iron.

2) It can be fitted on the table of the machien as upright and horzontal, the bottom of upright and horzontal is vertical. Centered clamping of workpiece is pressured on the v-block by two wobbing movable jaws. 

3) According to the diameters of its holding part, the double side v-block can be placed reversibily. The vice is fitted with a stop for location of the parts. 

4) It is used to help machines in marking some kinds of slots, holes and faces, suitable for holding the workpieces of cylinder.