Mini size DC 2.4~30V break the conventional voltmeter new design can work for 3V 5V 9V 12V 24V no need to stable voltage. With standard leading cable convenient to connect with car/battery cart/motorcycle Reverse connect protection function line will not be burn. The highest input voltage can't more than 30V or it will be burnt the digital will change with the measuring voltage. When the testing voltage under 10V show 2-digital afther the decimal point; 1-digital after decimal point when above 10V. Can satisfy the user's demands for the measuring precision and higher voltage measuring. The working conditions: lowest working voltage: +2.4V highest working voltage: +30V. Working temperature: -10~+65 degree celsius. Working humidity: 10~80%(no condensation). Working air pressure: 80~106kPa. Sun: no direct illuminate. Features: Good stability high measurement precision; Standard size and easy to install. Power supply adopts the polarity protection circuit.