The Laser Dimension Master II is an ultrasonic distance measuring device that measures up to 50 feet indoors and is accurate to 99%. Ultrasonic measuring devices are easier to use than roll-up tape measures. One person can make quick and accurate room measurements in seconds. Risk of injury on step stools or ladders associated with floor-to-ceiling measurements are also eliminated. The compact unit is 5 inches long, comes with a protective cover, and has a built-in laser pointer.