Two hands each holding a ruler of David, alternately moved in parallel. The main role: Before the graphic work to draw lines with title or title, the degree or quantity of title with title. Use: When performing the movement operation, the appropriate force to suppress the static hand foot, one hand pushing the moving feet, the two feet alternately move in parallel to the required position. Alternate movement, to avoid static movement of the foot. Colour:Silver Material:Acrylic Size:450mm Package Contents: 1 * Parallel table rule Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.