Lightweight, safe and compact. Carry inside car or truck. Ideal for taking fast and accurate vertical measurements of over head lines, highway clearances, structural heights and checking sag. Eye-level reading models eliminates need for calculations. Extended height is shown at top of base section. Positive locking sections and accuracy of measurement assured by fast acting spring loaded pin lock at base of each section, light weight bronze hook on tip end. All parts are standardized for quick, economical replacement.