The voltmeter can be used to measure the voltage of 18650 batteries, mobile lithium batteries, nickel metal hydride batteries and other battery packs, as well as the voltage of motorcycles, cars and other batteries, and can also be used for other voltage measurement purposes. This package contains 4 colours Mini Digital DC Voltmeter: Red (2.5V - 30V), Yellow (2.6V - 30V), Green (2.6V - 30V), Blue (3.2V - 30V). Equipped with two wires, convenient and simple wire connection, easy to connect to the car/battery car/motorcycle car line.With reverse polarity protection, the wire is not burned when the connection is reversed. The resolution is 0.01V when the voltage is measured below 10V; Resolution is 0.1V for voltage above 10V. This can ensure the accuracy of the measurement, but also the need to measure higher voltages. Specification: Operating Voltage: DC2.4~40V Detection voltage: DC2.4 ~ 30V Working current: