Voltmeter is made of plastic with a glass cover face. It is of top quality, durable and affordable.It is an instrument for measuring electric potential in volts and can also be used for measuring difference between two points in an electric circuit. Analog voltmeters move a pointer across a scale in proportion to the voltage of the circuit; digital voltmeters give a numerical display of voltage by use of an erVoltmeter is made of plastic with a glass cover face. It is of top quality, durable and affordable.It is an instrument for measuring electric potential in volts and can also be used for measuring difference between two points in an electric circuit. Analog voltmeters move a pointer across a scale in proportion to the voltage of the circuit; digital voltmeters give a numerical display of voltage by use of an er