It's easy to measure curved, horizontal and asymmetrical surfaces.
  Weighs less than 2 pounds.
  Measures 9,999 feet, 11 inches (or 9/10ths of a foot with engineers' models) 
  without resetting.
  Three-section handle telescopes up to 38 inches so you can measure without bending.
  Handle telescopes down to 17 inches to fit into a toolbox or standard briefcase.
  Adds while rolling forward and subtracts when pulled in reverse.