DC voltmeter is a measuring instrument, which is used to measure the DC voltage across any two points of an electric circuit . ... It basically limits the amount of current that flows through the galvanometer in order to prevent the meter current from exceeding the full-scale deflection value. Video Specifications: Model NO.: LDP3-AV Customized: Customized Origin: China Display: Digital Dimension: 96mm*48mm Transport Package: Carton Package includes: 1 x LIRRD Digital DC Voltmeter LDP3-AV