The Skyndex Digital Skinfold Caliper with the Slaughter-Lohman 2-Site formula was developed to use with children 8-18 years of age and is a fast way to assess your class or youth sports team's Body Composition. Simply select the gender with one dial. There are 2 dial settings on this caliper; 1 for Male, 2 for Female. This makes assessing Body Composition a 30 second job without the problem of data entry errors! Features: 2-Site Slaughter-Lohman Equation built in, 1 dial to select Gender, No data entry errors, Built in immediate %Fat calculation, 9v or 110v operation, Foam lined ABS plastic carrying case, calibration dowel and Power Plug included, 1 Year warranty included.