The E-Z Read Grade Rod reads the exact height above or below grade. No Adding- No Subtracting- No Errors! It does the math for you. Heavy duty aluminum with hard coat anodized finish, extends to 10 feet, large easy to read numbers with 5 foot reading scale for laser or optical instrument use. You can use your existing detector clamp with the E-Z Read Rod. The E-Z Read Rod extends to 10 feet and reads the exact height above or below grade. NO MORE MATH-NO MORE ADDING OR SUBTRACTING-NO ERRORS!