Unique patented oval shape permits equal size graduations fll-length, prevents rod from folling and is wasier to hold. Numerals and graduations are epoxy-protected for maxumum wear-resistance and sized for maximum relability. Sections cushioned with glides to prevent wear. Linear accuracy exceeds 1 in 4,000. Rods have height measuring gauge on back side. Female threaded hole on top for mounting a mini prisim.