The Martindale Proving Unit PD440 with Voltage Indicator V113800 is a high-quality voltage detector designed for industrial use. With a DC frequency range of 50Hz and a maximum voltage of 430V, this unit is suitable for measuring high voltage levels. The contact voltage detector type ensures accurate readings, while the CAT III rating provides a safe measurement category. The unit comes with a convenient carry case, making it easy to transport and store. Ideal for professionals in the electrical industry, this Martindale proving unit offers reliability and precision in voltage detection.