4 function in 1 detector,ultrasonic distance,Metal, Voltage and Stud Detector Features:1) Measures from 2 feet up to ... measure6) Easy-to-read LCD7) Built-in calculator for measuring areas and volumes8) Adds and subtracts linear measurements, area and volume9) Memory function10) Choose from ... by one piece of 9V battery (battery not included) 4-In-1 Distance, Metal, Voltage and Stud Detector