The ultrasonic Laser Dimension Master II distance measuring device measures up to 50 feet indoors and is 99% accurate, the maker says. The unit displays standard or metric distances on a large backlit LCD screen. The tool makes length and width measurements quick and easy and eliminates the need for ladders or step-stools for floor-to-ceiling measurements. At just 5 inches long, the LDM II fits easily in a shirt pocket or toolbelt and also has a built-in laser pointer. Calculated Industries | 800.854.8075 | calculated.com